Tuesday, September 30, 2008

Lesson 17: DR Plots

Deduced Reckoning aka Dead Reckoning

De(a)d Reckoning (DR) is nothing more than projecting a vessel’s intended course or track line from a fixed or known position by using true direction, speed, time, and distance to be traveled. “I reckon I’ll be there at 1020.” DR is one of the simplest and oldest methods of navigating in which a vessel’s position is deduced or computed mathematically in relation to a known point of departure. Dead reckoning is always used every time a vessel is underway. Do DR’s at least once hour, on the hour. The underlying reason for using DR is that a navigator can reasonably determine of his vessel’s most probable position without taking a fix. Dead Reckoning is the process of determining a vessel’s present location or future position along a known or projected course line from a previously known position by using the vessel’s actual or anticipated course, speed, and run time. The effects of current or wind are not considered in determining a DR position.

Some things to consider when Dead Reckoning:

1.Be neat, accurate, and complete. You will be less likely to make mistakes if you properly notate your work on the chart. Plus you'll have the information available if you need to refer to it at a later time.

2.The DR course (or track) is always plotted in degrees true. That means your compass course will have to be adjusted for variation and deviation.

3.The DR track always starts from a known location (your Fixed position).

4.The speed you use for DR is always your boat's known speed through the water. Don't use it's speed over ground. What's the difference? Your boat's speed through the water is just that. It has nothing to do with the actual speed that you're making over the sea bottom. The progress of a boat is influenced by many factors. You should measure your vessel's speed through calm water on a windless day with the use of a log (a boat speedometer) or some other method, and correlate it with engine RPM. This way you'll know your speed by looking at the tachometer. If you know that your boat goes 10 knots at 2000 RPM in a calm sea, and you're going into a 2 knot current, your speed over ground (SOG) may be 8 knots, but for your DR use the 10 knots. You'll apply corrections later.

Lesson 16: Speed, Time and Distance Problems

1. At 1056 your GPS shows your position as 36º 58.0 N 075º 42.0 W. At 1131 the GPS shows your position at 37º 08.5 N 075º 40.1 W. What was the speed made good (SMG) between the fixes?


2. At 0914 you are at the Chesapeake Bay Entrance Channel Buoy CBJ. What is your ETA at Chesapeake Channel between Trestle B and Trestle C of the Chesapeake Bay Bridge and Tunnel if you are making 10.9 knots?


3. While outbound in Thimble Shoal Channel, you are abeam of both Trestle “A” and “B” at 0707 while steering 108º T. At 0731, you take the following bearings PMC while steering 117º PMC: Cape Henry Light 144º, Cape Charles Light 040.5º, Thimble Shoal Tunnel South Light bearing 290º. What was the speed made good between 0707 and 0731? (Use 9º W variation and the compass deviation table found elsewhere in this study guide).

A.9.6 kt.
B.9.4 kt
C.8.9 kt
D.8.6 kt

4. At 1440 you are steering 005º T for a light dead ahead at a distance of 14 nm. You intend to make the light at 1625 to meet a pilot boat. What is your required speed to make at this light at 1625?

A.7.4 kt.
B.7.7 kt.
C.8.0 kt.
D.8.5 kt.


1. C
2. B
3. C
4. C

Weather Quiz..........

1. Compared to cold, warm air can hold:

A. more water vapor
B. less water vapor
C. the same amount of water vapor
D. no water vapor

2. Air can become saturated by:

A. raising the temperature
B. lowering the temperature
C. adding more water vapor
D. (B) and (C) above

3. The water in clouds at extremely high altitudes is usually:

A. liquid
B. vapor
C. frozen
D. steam

4. Fog formed by the horizontal movement of an air mass over a surface of different temperature is called:

A. advection fog
B. radiation fog
C. frontal fog
D. convection fog

5. A snow flake is:

A. a rain drop that froze
B. water vapor that condensed at freezing temperature directly into a solid state
C. water vapor that condensed to liquid and then was lifted by air to a freezing temperature
D. none of the above

6. If it’s impossible to avoid a hurricane in the Northern Hemisphere, the most favorable place to be when the storm passes is in:

A. the dangerous semicircle
B. the eye (center) of the storm
C. that half of the storm lying to the right of the storm’s path
D. that half of the storm lying to the left of the storm’s path

7. If the sky is clear, with the exception of a few cumulus clouds, it would indicate:

A. rain
B. hurricane weather
C. fair weather
D. fog setting in

8. Stormy weather is usually associated with regions of:

A. low barometric pressure
B. high barometric pressure
C. steady barometric pressure
D. changing barometric pressure

9. Most high pressure areas in the United States are accompanied by:

A. precipitation
B. clear, cool weather
C. humid, sticky weather
D. cool, fog

10. The form of a cloud often known as “mackerel sky” which is generally associated with fair weather is:

A. nimbostratus
B. stratus
C. altocumulus
D. cumulonimbus


1. A 5. B 9. B
2. D 6. D 10. C
3. C 7. C
4. A 8. A

Monday, September 29, 2008

World's Largest Cruise Ship....

It's a huge program....the mv Celebrity Solstice...
315 meters long!

SPV Log and Emergency Requirements

46 CFR 122.702 and 46 CFR 185.720

Weekly maintenance and inspections

(a) Each survival craft and launching appliance must be visually inspected to ensure its readiness for use.
46 CFR 122.722 and 46 CFR 185.722

Monthly inspection

(a) Each survival craft, rescue boat and launching appliance on a vessel must be inspected monthly, using the manufacturers instructions to make sure it is complete and in good order.
46 CFR 122.520 and 46 CFR 185.520

Abandon ship and man overboard drills and training

(a)The master shall conduct sufficient drills and give sufficient instructions to make sure that all crew members are familiar with their duties during emergencies that necessitate abandoning ship or the recovery of persons who have fallen overboard.
(b)Abandon ship and man overboard drills and training shall be logged or otherwise documented for review by the Coast Guard upon request. The drill entry shall include the following information:

(1)The date of the drill and training; and
(2)General description of the drill scenario and training topics.
46 CFR 122.524 and 46 CFR 185.524

Fire fighting drills and training

(a)The master shall conduct sufficient fire drills to make sure that each crew member is familiar with his or her duties in case of a fire.
(b)Fire fighting drills and training shall be logged or otherwise documented for review by the Coast Guard upon request. The drill entry shall include the following information:
(1)Date of the drill and training; and
(2)General description of the drill scenario and training topics.

A Quiz.........

1.On charts of the US waters, a magenta marking is not used for marking a:
A. 5-fathom curve.
B. Prohibited area.
C. Lighted buoy.
D. adio-beacon.

2. The only cylindrical chart projection used for navigation is the:
A. Lambert conformal.
B. Mmercator.
C. Azimuthal.
D. Gnomonic.

3. The equator is:
A. The primary great circle of the Earth perpendicular to the axis.
B. The line to which all celestial observations are reduced.
C. The line from which a celestial body’s altitude is measured.
D. All of the above.

4. Chart legends which indicate a conspicuous landmark is printed in:
A.Capital letters.
B. Italics.
C. Boldface print.
D. Underlined letters.

5. The description “Racon” besides an illustration on a chart would mean a:
A. Radar transponder beacon.
B. Radar conspicuous beacon.
C. Radar calibration beacon.
D. Circular radio-beacon.

6. 17 degrees of latitude is equal to:
A. 68 miles.
B. 510 miles.
C. 1020 miles.
D. 4080 miles.

7. Charts should be corrected by using information published in the:
A. Light List
B. Notice to Mariners
C. Coast Pilot
D. All the above

8. The compass rose on a nautical chart indicates both variation and -
a. Deviation
A. Annual Rate of variation change.
B. Precession.
C. Compass error.

9. A chart with a scale of 1:600,000 is classified as:
A. Sailing chart.
B. General chart.
C. Coast chart.
D. Harbor chart.

10. Which aid is not marked on a chart with a magenta circle?
A. Aero light.
B. Radar station.
C. Radar transponder beacon.
D. Radio-beacon.

1.A 6. C
2. B 7. D
3. A 8. B
4. A 9. A
5.A 10. A

Sunday, September 28, 2008

Lesson 15: Speed, Time, and Distance....

Distance, Time, and Speed (DTS) Calculations

For a variety of navigation problems, we need to know how to solve for speed, time, and distance. The basic DTS60 expression has it all. By knowing at least two values for Time, Speed, and Distance values in relation to 60 minutes, we can solve for any unknown value.

Formulas: S = (D X 60)/ T T = (D X 60)/S D = (S X T)/60

Need to Know

One degree of indicated latitude is equal to sixty (60) nautical miles in distance. Each degree is divided into sixty (60) minutes, with each minute equal in distance to one (1) nautical mile. As already mentioned, each minute is then divided into tenths (or seconds).

To measure the distance between two positions on a chart or points is to compare this distance to an adjacent latitude scale. Distances in nautical miles or fractions of a mile can be directly read from the indicated degrees, minutes, and tenths of latitude.

Remember DTS60 for Distance, Time, and Speed calculations. For example, to determine a vessel’s Speed, first calculate Distance traveled (set dividers to adjacent latitudes for distances) divided by the amount of time (in minutes) needed to traverse the indicated distance. In other words, Speed is equal to Distance multiplied by 60 divided by Time (S = D X 60 / T). Time traveled is equal to Distance multiplied by 60 divided by Speed (T = D X 60 / S). Distance traveled is equal to Speed multiplied by Time divided by 60 (D = S X T / 60).

Time values must be expressed in total number of minutes not hours and minutes. Therefore we need to use 24 hour time. For example, 2 hours and 34 minutes is expressed as 154 minutes. Learn to use 24 hour or military-time, TRY TO remember that there are only 60 minutes in an hour when doing time calculations not 100 minutes !!!!

D – 60 - StreeT

Saturday, September 27, 2008

Lesson 14: Tides and Currents

Need To Know

Tide is the vertical movement of water. When water momentarily stops rising (flood) or falling (ebb), (such as a baseball “hangs” before it begins to fall when thrown upwards), this moment is called the stand.

Wet rock = ebb. Dry rock = flood.

Sounding Datum a designated reference point which tide heights are compared to.

High Tide is the highest level of water caused by the ascending or flood tide during a tidal cycle. This height is expressed in relation to the sounding datum.

Low Tide is the lowest level of water of water caused by the descending or ebb tide during a tidal cycle. This height is expressed in relation to the sounding datum.

Range of Tide is the vertical difference between the high and low water levels during a tidal cycle.

Under stand the differences between Mean Higher High Water (MHHW), Mean High Water (MHW), Mean Low Water (MLW), and Mean Lower Low Water (MLLW) and how this impact chartered depth soundings and vertical clearance under bridges (MHW).

Semidiurnal tide is probably the most common of the world’s tide pattern where there are two high and two low tides occurring during the tidal day (24 hours 50 minutes in duration). Diurnal tide is where there is only one high and one low tide occurring during the tidal day. Mixed Tide is a semidiurnal pattern characterized by a greater variation in range in one of the pairs of high-low tides occurring during the tidal day. This type of tide is commonly seen along the US Pacific coast.

Current is the horizontal movement of water. Current is comprised of both direction (set) and velocity (drift). Slack or slack water occurs when there is no horizontal movement of water or current.

Most open ocean tidal currents rotate in direction through a tidal period of 12 hours 25 minutes.
There are no slack waters in a rotary current. Instead, there is a minimum and maximum
current, separated by three hours, thus corresponding to low and high tides.

Tide and current tables make use of a primary or Daily Predictions reporting station in which daily predictions are made. From this station, time, depth, and current speed corrections are made for other Subordinate or secondary coastal locations within the same geographic area.
Always correct for Day Light Savings Time (DST) when required. Not all charts observe this correction and accordingly must be made by the navigator.

Tidal Datums and Tidal Epochs –Sea level averages are taken over several years to obtain a tidal datum - a vertical reference based on some phase of the tide - to slow the process if only temporarily. This is a workable idea because, in addition to sinking crusts and melting ice, tidal variations also have their effect on sea level. One such effect is the 18.6-year cycle of the lunar nodes – a cycle accompanied by variations in tidal range. Another force for change is the annual variation in solar declination that modulates solar heating and density of ocean waters. To account for both, a 19-year period of water level averaging – the National Tidal Datum Epoch (NTDE) – has been established by NOAA/NOS in the United States. NTDEs have included the years 1924-1942, 1941-1959, 1960-1978, and most recently, 1983-2001. NTDEs thus are being updated roughly every twenty years.

Here are the basic definitions for tidal datum commonly used in the U.S. and its territories:

Mean Sea Level (MSL) – Arithmetic mean of hourly water levels observed during current NTDE.
Mean Higher High Water (MHHW) – Mean of higher high water heights during current NTDE.
Mean High Water (MHW) – Mean of all high water heights observed during current NTDE.
Mean Low Water (MLW) – Mean of all low water heights observed during current NTDE.
Mean Lower Low Water (MLLW) – Mean of lower low water heights during current NTDE.
Mean Tide Level (MTL) – A datum located midway between MHW and MLW; i.e., MTL = ½ (MHW+MLW).

Friday, September 26, 2008

Survey Recommendations........

Here are recommendations that I made during a recent survey of a Luhrs sportfishing boat....

1. FOUND: In the machinery space, the main engine the raw water cooling water seacock (1-1/2” gate valve) was found to non-operational and has evidence of alloy breakdown. RECOMMEND: This seacock should be replaced as required with a marine-grade valve installed as per accepted marine industry practices. Buyer has been made aware of this condition.

2. FOUND: In machinery space, lead acid storage batteries properly secured and in spillproof trays with the terminals not protected to prevent accidental sparking – fires as per ABYC and NFPA 302 recommendations. RECOMMEND: Provide and install adequate battery terminal protection as required to prevent accidental sparks which could cause fire – explosion aboard the vessel. Buyer has been made aware of this condition.

3. FOUND: In forward machinery space area, the suction line (white PVC pipe) for one of the vessel’s dewatering pumps is not supported at the forward bulkhead and potentially could come in contact with the engine’s drive belt assembly. RECOMMEND: This suction line should be well supported with clamps at the bulkhead. Buyer has been made aware of this condition.

4. FOUND: Expired USCG required and approved visual distress devices (flares). RECOMMEND: Supply and have onboard at least three (3) USCG approved visual distress devices before getting underway as per 33 and 46 CFR. Owner and buyer have been made aware of this condition.

5. FOUND: In machinery space, at after end of exhaust manifold, starboard engine, leaking cooling water hose connection. RECOMMEND: Inspect and repair as required to provide water and gas tight hose connection. Hose connections should be secured with two (2) all stainless steel clamps.

6. FOUND: The vessel’s Washington State assigned HIN - WAZ was not visible on the upper starboard transom area as required by state law. RECOMMEND: Provide and install a permanent engraved placard with the vessel’s assigned state HIN (Hull Identification Number). with the hose connection made with two (2) all stainless steel hose clamps as per ABYC. Buyer has been made aware of this condition.

Lesson 13: Weather


Clouds – Clouds are formed when warm, moist air rises and is cooled to the dew point. The water vapor condenses around tiny particles of dust to form droplets. Although the variety of clouds are almost endless, the following are the main types.

High Clouds – occur above 20,000 feet and are composed mainly of ice crystals. The major types of high clouds are Cirrus (ci), Cirrocumulus (cc), and Cirrostratus (cs).

Middle Clouds – occur between 6500 and 20,000 feet. Included in the middle cloud group are

Altocumulus (ac) and Altostratus (as).

Low Clouds – are found below 6,500 feet. Nimbostratus (ns), Stratus, Stratocumulus (sc), and Cumulus (cu) are types of low clouds.

Vertical Development Clouds – This type of cloud may, form at low level and grow as high as 45,000 feet. The “thunderhead” (cumulonimbus, cb) cloud that is often shaped like an anvil is an example of a cloud with vertical development.

Atmospheric Pressure – The pressure exerted by the weight of the earth’s atmosphere which is about 14.7 pounds per square inch. Atmospheric pressure is generally measured in either inches of mercury or in millibars (mb). Millibars are generally used in marine weather and inches of mercury are generally used for land weather in the U.S.. The average pressure worldwide is about 1013mb. Extreeme values are 950 and 1050 – though greater extremes are possible during severe weather such as Hurricanes. Atmospheric Pressure is measured using a barometer. Low pressure is usually associated with “bad weather” – stormy conditions. High pressure is usually associated with “good weather” – clear and cool.

Barometer - the most common type used is the aneroid barometer which determines atmospheric pressure by the effect of such pressure on a thin metal cylinder from which the air has been partly evacuated. Aneroid means without liquid, as opposed to a mercury barometer which contains liquid mercury.

Wind – can be caused by many different factors. On the large scale, the main factor is the movement of air from a high pressure area to a low pressure area. On the earth’s surface, this flow from high to low pressure does not follow a direct path. It is deflected by the earths rotation. Surface winds encounter friction from geographical features or rough seas which tend to deflect the surface winds. An “anemometer” is used to measure wind speed, while a “wind vane” is used to measure wind direction. An installed anemometer is an instrument fixed somewhere aloft, usually at the masthead. The winds blow the propeller attached to one end of the vane that pivots. The whirling propeller revolves a spindle, attached with a synchro-repeater in the pilothouse or chart house bulkhead.

As a high or low pressure system moves through an area, there is always a noticeable change in wind direction. When the wind changes direction in a counterclockwise direction it is called a “backing” wind. A wind shifting in a clockwise direction is called a “veering” wind.
Radiation Fog - Radiation fog is formed on clear, still nights when the ground loses heat by radiation, and cools. The ground in turn cools the nearby air to saturation point, thus forming fog. Often the fog remains patchy and is confined to low ground, but sometimes it becomes more dense and widespread through the night.
After dawn, fog tends to disperse because it is 'burnt off' by the incoming solar radiation, some of which penetrates the fog and reaches the ground. The ground heats up, as does the layer of air near it. Eventually, the air reaches a temperature where the minute fog droplets evaporate and the visibility improves. However, in winter fogs can be very persistent.

Advection Fog - Advection fog is formed when very mild moist air moves over a cold ground. This can often happen in early spring when mild southwesterly winds moving across the country over snowy or icy ground. The lower layers of the air get cooled down rapidly to below the temperature at which fog forms.

Coastal Fog - Some coastal regions suffer from 'sea fog' which forms when moist air is cooled to saturation point by traveling over a cooler sea. The wind may then take the fog into coastal regions. This type of fog tends to occur in spring and summer, and particularly affects inland waters.

Steam Fog - 'Steam fog or sea smoke' is sometimes seen when cold air moves over much warmer water especially in the morning or late evenings on large rivers and or lakes. When cold air passes over much warmer water the lowest layer of air is rapidly supplied with heat and water vapor. Mixing of this lower layer with unmodified cold air above, can, under certain conditions, produce a super saturated (foggy) mixture.

Freezing Fog - Freezing fog is composed of super-cooled water droplets (i.e. ones which remain liquid even though the temperature is below freezing-point). One of the characteristics of freezing fog is that rime - composed of feathery ice crystals - is deposited on the windward side of vertical surfaces such as superstructure, rigging, masts, stanchions, and radio antennas.

Need To Know

Cold air is denser than warm air and when pushed by weather systems forces a wedge under the warm air ahead of it. The denser air exerted higher pressure in the atmosphere reflected in a rising reading on a barometer. The reverse is true of warm air following a cold air mass. In each case the change in barometer indicate an instability which can cause bad weather conditions: high winds, reduced visibility in fog or rain, and lightening storms. A falling barometer often means the approach of a weather front or deteriorating weather, as a rising barometer forecasts good weather. The faster the barometer changes the more dramatic the weather.
If air is warm it can hold more water vapor than if cold. Capacity varies with temperature and when air has all the water vapor it can hold, the atmosphere is said to be saturated.

The temperature at which air is completely saturated is called the dew point, below that mark, condensation can take place.

The measure of the water vapor in the atmosphere is called absolute humidity. When we compare that amount with what the air can hold, the term is called relative humidity.

Fog is like a cloud, the product of condensed water vapor.

Air masses do not tend to mix and dilute each other. Rather they collide along a battle line called a “front “and push each other around until one has nudged the other along by either undermining or by overriding.

Warm Front: Warm air slowly pushes over cold air. This front moves slowly, 10 to 15 knots, and the weather slowly changes to showers. However, this front can also bring strong winds and thunderstorms.

Cold Front: Cold air rapidly pushes beneath warm air. This front can move fast, up to 25-30 knots, and weather deteriorates with rain, strong winds and thunderstorms.

Backing winds run counter-clockwise. Veering winds run clockwise.
Weather patterns in the mid-latitudes of the northern hemisphere generally track westward. Though this pattern does not seem to hold true on the west coast of the U.S.

Hurricanes have a navigable and un-navigable or dangerous semicircle. Ahead of the storm track (northern hemisphere), wind and sea carries vessels into the path of the storm, so don’t cross ahead of a storm unless you are more than 300 nm out. In the un-navigable semicircle, the wind is greater due to the pressure augmented by the forward motion of the storm. In the navigable side, wind decreases by the storm’s forward motion. If you find your vessel in the dangerous semicircle, place the wind and sea on the starboard bow and hold it. In the navigable semicircle, place the wind and sea on the starboard quarter.

Lesson 12: Cross Bearing Fix

Using NOAA Chart 12221 TR, Variation 9W, and the deviation table from Lesson 10 -

Relative Bearings, Lines of Position and Cross Bearing Fix

You may determine the position of your boat by many methods of piloting. The line of position is common to all methods. For example, if you observe a charted standpipe and a charted flag pole in range (lined up), you are somewhere on the line drawn from the standpipe to your boat through the flagstaff. This line is called a range line and is a line of position (LOP). Although a single visual observation can provide a line of position, it does not establish a position. You are located somewhere along this LOP. If an LOP is obtained by magnetic compass, the compass bearing must be corrected to true degrees by apply variation and deviation for the compass heading at the time the bearing was obtained.

Remember a single line of bearing gives you a LOP. Your boat is somewhere along that LOP. You also know that you cannot accurately fix your position by a single LOP. You must plot two (2) or more intersecting LOP’s to obtain a Cross Bearing Fix. The greater number of lines of position intersecting at the same point the greater the confidence in the fix. For a fix to be most accurate, LOP’s must be derived from simultaneous observations or bearings time corrected. In the normal practice of small-boat navigation, you may take two (2) or more bearings, one after the other, and these are considered to meet accuracy requirements.

Bearings can be taken by sighting across a compass, using a hand bearing compass, relative bearings or by RADAR. The direction to the object sighted is recorded. When using cross bearings the fix is obtained by taking bearings on two (2) well defined – charted objects and plotting the observed bearings onto a chart. A more accurate fix may be obtained by taking a third bearing on another well defined object. There should be a separation of at least sixty (60) degrees between lines of position.

Need to Know

A line of position or relative bearing is where the observer and sighted object is assumed to be located somewhere in the same visual “range”.

Two intersecting lines of position taken on two separate sighted objects (objects with known, charted positions) can provide the position of the observer.

Three lines of position on three separate objects (all with known positions), provide a far more accurate fix than using two lines of position.

Only a ship’s heading has a deviation value, relative bearings obtained from lines of position never have deviation values.

Relative bearings are expressed in relation to the ship’s steering compass.

Always work relative bearings up from magnetic steering compass readings to true direction before plotting on a chart.

Always plot bearings values in the correct direction and in true degrees “back” towards the respective sighted object used for that specific bearing or line of position.

Learning Exercise: Cross Bearing Fix

In the following problem set, you will be given the vessel’s heading per steering compass plus three relative bearings. Find Lat/Lon using this information. Remember that deviation is taken from the ship’s heading (SH), not relative bearing(s).

Remember !

Using only the ship’s heading to determine deviation value and use the same value for each “D” in table below. Remember, remember, and remember….bearings never have deviation values! Bearings never deviate, only a ship’s head deviates.

Work each relative bearing reading up to True degrees (- W + E).

On the chart, plot each reading in True degrees, in the correct direction, towards its respective sighted object.

At the point which the lines of position intersect indicate the vessel’s position at the time when the compass bearings were taken.

Drop the pencil in the geometric center of the triangle or cocked hat.


Learning Exercise:

1. You are on a course of 027º PMC when you take the following bearings PMC:

New Point Comfort Light “2” – 253º
Horn Harbor Entrance Light “HH” – 282º
Wolf Trap Light – 348º

What is the position of the fix?

A. LAT 37º 19.4’ N LON 076º 09.8’ W
B. LAT 37º 19.7’ N LON 076º 09.9’ W
C. LAT 37º 19.4’ N LON 076º 09.5’ W
D. LAT 37º 19.7’ N LON 076º 10.3’ W

2. You are on a course of 089º PMC when you take the following bearings on your vessel magnetic steering compass:

Great Machipongo Light “5” – 004º
Cape Charles Light – 253º
Sand Shoal Inlet South Light – 334º

What is the position of the fix?

A. LAT 37º 11.95’ N LON 075º 41.5’ N
B. LAT 37º 12.0’ N LON 075º 40.9’ W
C. LAT 37º 11.6’ N LON 075º 43.0’ W
D. LAT 37º 11.9’ N LON 075º 41.6’ W

3.You are on a course of 035º PMC when you take the following bearings per magnetic compass:
Cape Charles Light – 343º
Chesapeake Light – 131º
Cape Henry Light – 261º

What is the position of the fix?

A. LAT 36º 58.4’ N LON 075º 49.1’ W
B. LAT 36º 58.1’ N LON 075º 50.0’ W
C. LAT 36º 57.8’ N LON 075º 49.2’ W
D. LAT 36º 57.6’ N LON 75º 049.8’ W
4. You are on a course of 153º PMC when you take the following bearings on your ship’s compass:

Cape Charles Light – 345º
Chesapeake Light – 148º
Cape Henry Light – 241º

What is the position of the fix?

A. LAT 37º 01.6’ N LON 075º 50.9’ W
B. LAT 37º 11.5’ N LON 075º 50.1’ W
C. LAT 36º 57.6’ N LON 075º 51.6’ W
D. LAT 36º 57.9’ N LON 075º 50.8’ W

5. You are on a course of 060º PMC when you take the following bearings PMC:

Horn Harbor Entrance Light “HH” – 285º
New Point Comfort Spit Light “2” – 256º
Wolf Trap Light – 348º

What is the position of the fix?

A. LAT 37º 19.4’ N LON 076º 09.8’ W
B. LAT 37º 19.4’ N LON 076º 09.5’ W
C. LAT 37º 19.7’ N LON 076º 09.9’ W
D. LAT 37º 19.7’ N LON 076º 10.3’ W

1. B
2. C
3. C
4. A
5. B

Thursday, September 25, 2008

Is There a Sailor's Version of Mr and Ms Potato Head?

The things my wife Nannette and I do for ZM.......(a get together last night - just before my class - at Hotel Nexus here in Seattle)....actually we are working with Nexus to arrange for accommodations for out of town mariners to stay while taking classes here in Seattle and surrounding metro areas.........

Lesson 11: Finding Course Per Magnetic Compass

Use chart 12221 TR, a variation of 9 West and the deviation table from lesson 10 - find both the course per magnetic compass (PMC) and distance in nautical miles for the following questions.

1. From 37º 07.5’ N 075º 39.1’ W to 36º 57.0’ N 075º 41.0’ W

- ____________ degrees PMC Distance ________nm

2. From 37º 01.6’ N 075º 31.7’ W to 36º 57.0’ N 075º 41.0’ W

- ____________ degrees PMC Distance ________nm

3. From 37º 00.5’ N 075º 43.8’ W to 37º 00.0’ N 075º 30.0’ W

- ____________ degrees PMC Distance ________nm

4. From Wolf Trap Light to New Point Comfort Spit Light “2”

- ____________ degrees PMC Distance ________nm

5. From Chesapeake Light to Buoy “NCA”

- ____________ degrees PMC Distance ________nm


1. 200º PMC Distance = 10.7nm
2. 250º PMC Distance = 8.7nm
3. 099.5º PMC Distance = 11.1nm
4. 223.5º PMC Distance = 6.7 nm
5. 321º PMC Distance = 6.4 nm

Lesson 10: Magnetic Compass and Compass Error

On most NOAA general and harbor charts, a smaller compass rose is printed within the outer True degrees compass rose. This is referred to as a Magnetic compass rose. Instead of being aligned with a meridian of longitude, the magnetic compass rose always points in another direction, towards the earth’s magnetic North Pole (some 200 miles north of the Boathia Peninsula in Canada…the South Magnetic Pole is located in South Victoria Land in Antarctica). You can see this difference between both North poles on NOAA Chart 12221 TR as the two (2) north poles (True and Magnetic) vary in alignment with each other. This offset or angular difference is referred to as Variation and changes as a vessel’s position changes. In this instance, the stated variation is 10 minutes West (for the year 1990). Variation is the angular difference between the true north and the magnetic north pole. If the northerly part of the magnetic meridian lies to the right of the true north-pole, the variation is Easterly. If the northern part of the magnetic meridian lies to the left of the true north-pole, the variation is Westerly. As one travels on the Earth’s surface, the amount of this Variation changes as the angular difference in alignment between these two poles changes or varies and in some cases, this difference becomes zero (0) degrees. This only occurs when both poles are in direct alignment with one another.

General and harbor charts usually indicate the degree(s) of magnetic variation for its area of coverage. Before we can use a magnetic compass aboard any vessel, we first have to deal with all the magnetic influences that make it deviate from true geographical north-pole. Compass Error is the effect of two factors - variation and deviation.

When correcting from True degrees to Per Magnetic Compass (or PMC) - Westerly Variation and Deviation is always added and Easterly Variation and Deviation is always subtracted. Conversely, when correcting for a heading on the ship’s steering magnetic Compass or PMC back to a True direction, always subtract Westerly Variation and Deviation and always add Easterly Variation and Deviation.

Deviation is the magnetic influence on the compass card caused by external iron masses, structural components, electro-mechanical devices, and other electrical items or articles located onboard the vessel and will never change with ship’s position as variation does. Deviation only varies with changes in the vessel’s heading. Go to the Compass Deviation Table with either “C” or “M” to find Deviation values. Never use “T”!

Need to Know

The compass is a simple navigational instrument which uses magnetic attraction to determine circular direction. Since opposite magnetic poles attract, the fixed magnet on the compass card is attracted to the earth’s magnetic north pole. The compass card is aligned with the magnet(s) and always points towards magnetic north (excluding deviation). Remember – as the compass heading changes – the compass card does not move – it remains aligned with magnetic north.
Magnetic Variation and never, ever Deviation, changes with a vessel location at sea and will significantly vary from location to location and therefore, potentially from chart to chart. Although the learning exercises and exam questions will use the same “frozen 009º W”, correction factor for variation, out there, in the real world, the amount of magnetic variation changes from place to place on the earth’s surface. In addition, the actual variation changes on a yearly basis. Almost all NOAA general and harbor charts will have the annual increase or decrease in variation (including direction) clearly printed within the compass rose.
There are 32 cardinal points on a compass (each point equals 11¼ °).

To convert True direction to a Compass heading - use the following formula -T V M D C. This is where T means True degrees, V means magnetic Variation, M means Magnetic degrees, D means compass Deviation, and C means ship’s Compass.

When converting True to Magnetic, add westerly variation and subtract easterly variation. If correcting from Magnetic to True, subtract west variation and add east variation.

To arrive at Compass – correct Magnetic for Deviation caused by onboard magnetic sources. Deviation is always either East or West. Deviation is found on the Compass Deviation Table by using either Compass or Magnetic. Determine a Deviation value which most closely agrees with either Compass or Magnetic (interpolate).

Deviation changes as the ship’s heading changes.

By swinging the ship’s steering compass, the compass card’s Deviation from absolute magnetic truth can be defined in degrees (in a east or west direction) in the Compass Deviation Table. Therefore, Compass is a heading corrected for both Variation and Deviation or Compass Error.
To correct Compass heading to True direction, reverse the formula: C D M V T .
Always write the course in degrees clearly indicated by a T for True or M for Magnetic above the projected course line.
PMC indicates Per (steering) Magnetic Compass. PGC is Per (steering) Gyro-Compass.

Here’s How To Do It:

One of the easier ways to do compass calculations is to begin by writing down the first letters of the phrase “True Virtue Makes Dull Company” or just T – V – M – D – C in either a vertical or horizontal line with arrows indicating which direction you add east (subtract west) and add west (subtract east) and then do the math. Never get Deviation values from True, only from Compass or Magnetic.

Using 009 W Variation and 002 E Deviation.

True to Compass Compass to True

When Correcting “T” to “C” When Correcting “C” to “T”

Do this: + W à - E - W ß + E

True 115º 115º
Variation + 009º W - 009º W
Magnetic 124º ß (use this number to find D) 124º
Deviation - 001º E + 001º E
Compass 123º 123º (use this number to find D)


Ship’s Head Deviation (in degrees)
000 2 East
030 3 East
060 4 East
120 1 East
150 1 West
180 2 West
210 3.5 West
240 3 West
270 1.5 West
300 0
330 1 East
Remember – When going from True to Compass add Westerly Variation and or Deviation and subtract Easterly Variation and or Deviation.

When going from Compass to True subtract Westerly Variation and or Deviation and add Easterly Variation and or Deviation.

Refastening Plan or Schedule for Wood Boats


Acting upon the request of Mr Smith, the undersigned inspected underbody and topside fastenings of a Chris Craft yacht while it was blocked up at Boat Yard on 2008. Parties present at the time of inspection were Mr. Jones (shipwright) and the undersigned. The purpose was to make a better determination of the general condition of the hull fastenings and propose a refastening schedule.

With the aging of the fleet, as with most mid-century wood yachts (and small craft), the serviceability (viz., fitness for intended usage) of original metal hull fastenings has reached an observable end point. This event is not unexpected but rather expected given the nature of wood boat fastenings and should be dealt with in a systematic and prudent manner to preserve the seaworthiness of the vessel while not inflicting undue damage during restoration. This is particularly true with vintage Chris Craft yachts.

Regarding the subject vessel, numerous hull fastenings were opened up and or inspected along the waterline, garboard, and broad planks and on the transom – hood plank ends. In addition, since the last inspection, the vessel’s starboard topsides (amidships and aft) have been (nearly) stripped of all paint - down to bare wood from the waterline to the sheer. This allowed for a clear observation of the original fastening pattern and the nature - extent of previous refastening work. In addition, some underbody paint was removed to reveal additional exterior hull fastenings Based on these observations we can now address some of the concerns raised in the original survey report.

“The undersigned concluded the vessel has been subject to fastener wastage for some time and previously undergone some refastening (the extent and degree unknown at this time).” - We now know that this is indeed clearly the case. It would appear that approximately twenty (20%) percent of the exterior hull fasteners (found on the topsides and on the underbody) have been replaced (at an unknown date – evidenced by being bunged with a hard, dark colored, epoxy-like material rather that the original soft – white bung compound commonly used by Chris Craft). In addition, the replacement fasteners are Philips (head) bronze wood screws and not the original Reed-Prince bronze wood screws. The existing re-fastening pattern seems somewhat capricious (probably based on temporal needs), but never-the-less represents a material refastening of both planks (on frames) and (seam) battens. The condition of these fasteners is good and very serviceable.

“No proud or rattling planks were observed. The seams visually appeared to be tight and stable.” – When initially inspected, the undersigned found only a very small amount of bilge water – a clear indication of hull tightness and garboard stability. In addition, since the time the vessel has been hauled and blocked (out of the water nearly three (3) weeks), very little, if any, movement, cracking, or material changes in the seams, frames, timbers, and or butts was observed…a good indication of the integrity of the existing hull fasteners. To be sure – as indicated in the original report, “In general, a substantial amount of the removed fasteners were found to be in serviceable condition with sharp pitch showing little, if any alloy break-down (and tightened up well when replaced).”

“A fair amount of the fasteners (approximately 25 - 30%) where found to have moderate to serve alloy break down with one (1) unserviceable fastener replaced with a new bronze fastening). Some screw heads are soft and brittle, and three screw heads partially broke off, while attempting to remove the fastener. The scope and location of suspect fasteners varied but generally the portside underbody from the garboard plank up to and slightly above the waterline produced the greatest amount of suspect fasteners.” – Regardless of past refastening work and the number of still serviceable fasteners, a fair amount of the existing fastenings are at the end of their serviceable life and in need of replacement. When dissimilar metals are in damp, salt-water wet wood they become electrically connected and corrosion occurs. With unserviceable bronze fasteners, the metal becomes pink in color and brittle, and only those would be renewed. Generally speaking, the majority of (potentially) wasted fasteners should be found amidships and aft on the quarters (underbody, transom, and topsides up to about one (1) foot above the waterline). It was originally contemplated by the undersigned that a schedule to include immediate sister fastening with a delayed king frame refastening schedule was possible…but now, given the fact that the vessel’s topsides are being taken to bare wood in preparation of painting, an opportunity to refasten (with minimum damage to the vessel) presents itself.

Based on the information presented herein regarding the scope and number of observed existing replacement fasteners and the extent of observed unserviceable fasteners, the following re-fastening schedule is recommended. The undersigned reserves the right to revoke, amend, modify and or revise any and all recommendations and conclusions found herein and elsewhere based upon subsequent discoveries and or observations.


It is recommended that the following specific exterior original hull fasteners (not those used in previous refastening work) be replaced - renewed (a section at a time) while the vessel is presently hauled and blocked:

Starting amidships (both port and starboard sides) then aft and forward, commence (plank on) king frame and butt block refastening beginning about one (1) foot above the waterline and continue down to the garboard plank at the keel. Open up and replace existing original and or wasted hull fasteners with same size (approximately #8) and correct length marine-grade bronze wood screws. Over-size fasteners should be used those instances when a new fastener will not properly tighten up. Sister fastening should be used when an existing fastener cannot be removed without causing damage to the wood hull – frame structure. A sister fastener should be fitted when it does not compromise the adjacent wood structure, (that is – to cause cracking, splitting, or create a weak spot in the plank, butt block, and or king frame).

Suspicious original batten fasteners should be opened up, inspected, and replaced when in question vis-à-vis wasted adjacent frame fastenings. As required, replace existing original and or wasted hull fasteners with same size (approximately #8) and correct length, marine-grade bronze wood screws. Over-size fasteners should be used in those instances when a new fastener will not properly tightened up. Sister fastening should be used when an existing fastener cannot be removed without causing damage to the wood hull structure. A sister fastener should be fitted when it does not compromise the adjacent wood structure,

The original transom planking fasteners should be opened up, inspected, and replaced from about one (1) foot above the waterline and continuing to down to the bottom of the transom. Replace existing original and or wasted fasteners with same size (approximately #8) and correct length marine-grade bronze wood screws. Over-size fasteners should be used in those instances when a new fastener will not properly tightened up. Sister fastening should be used when an existing fastener cannot be removed without causing damage to the wood hull – frame structure. A sister fastener should be fitted when it does not compromise the adjacent wood structure.

The hood plank end (original) fasteners should be should be opened up, inspected, and replaced from about one (1) foot above the waterline and continuing downward. Replace existing original and or wasted fasteners with same size (approximately #8) and correct length marine-grade bronze wood screws. Over-size fasteners should be used in specific instances when a new fastener will not properly tightened up. Sister fastening should be used when an existing fastener cannot be removed without causing damage to the wood hull – frame structure. A sister fastener should be fitted when it does not compromise the adjacent wood structure.

Only new, marine grade bronze fastenings should be used. The use of dissimilar metal fasteners is strongly discouraged and must be avoided. Fastener openings should be completely and securely plugged with either glued mahogany bungs (slicked clean, filled, and faired) or sealed - faired with a marine grade underwater seam compound to protect fastenings and restore proper cosmetic appearance.

In the event that a section of good serviceable original hull, topsides, or transom fasteners is found and documented (for example, working from an area of non-serviceable fasteners into an adjoining area where the vast majority of existing fasteners are visually free of wastage and alloy break down), then scheduled refastening may be dispensed with in that specific area only. All fasteners (as specified herein) must be renewed unless determined otherwise by a competent shipwright and or marine surveyor.

In the event that damaged, soft, weakened, or decayed (rot fungi) wood is discovered, the nature and extent of which must be determined. Any replacement or repair to existing wood structure(s) should be reviewed by a competent shipwright.

Written and photographic documentation regarding the location - condition of existing, new, and remaining fasteners (frame and plank number) along with any relevant observation regarding the condition of the wood structure should be kept and preserved for future reference. Old fasteners should be retained for inspection.

All work must be carried out in accordance with accepted marine construction practices, with demonstrable good craftsmanship, and with due regard to the nature, scope, and importance of maintaining the seaworthiness of the vessel.

The completion of the proposed fastening schedule does not relieve any obligation or requirement to dispense with regular fastener inspections and or future refastening due to on going fastener wastage. All Observations, Non-Standard Conditions, and Recommendations contained in the original survey report remain in effect.

The opinion and report herein is given without prejudice to the questions of rights, interests, and or liabilities on the part of any and all persons concerned.

Wednesday, September 24, 2008

Friday Harbor Zenith M100 Class....

My good friend Capt. Richard Rodriguez leads his Friday Harbor (San Juan Island - Washington State) Master 100 ton class through the 72 COLREGS.....could it be red over white fishing at night - no masthead light?
Richard just started his sixth year as an USCG approved instructor.

Steel Fasteners...Going, Going, Gone......

Just one more prattle on fasteners in old wood boats. Here's a pic from a survey on a large historic tug boat here in Seattle. She has fir (4" planks except 5" garboards) on fir frames fastened with tree-nails except on the garboard plank (where it would be difficult at best to do) - which is fastened with husky steel boat nails....that are slowly going away..........

Summer's End.....

Change is in the air...some pics from Roche Harbor, Queen Anne, San Juan Islands, and Lake Union of summer's last days here in the PNW......BTW - who is that guy? My boat got a pointy end just like yours!

Lesson 9: Circular Direction.......

The chart’s compass rose indicates the direction of the earth’s true North Pole. As you will notice on NOAA Chart 12221 TR, true north is indicated by zero (0) degrees with an arrow. In a clockwise rotation, due east is indicated at ninety (090) degrees, due south at one hundred eighty (180) degrees, and finally, due west at two hundred seventy (270) degrees for a total of three hundred sixty (360) degrees. The compass rose’s north-south orientation always exactly matches that of meridians of longitude while its east-west orientation exactly matches parallels of latitude. Therefore, it becomes a simple matter to indicate a course or bearing from one position to another any where on the earth’s surface by making a reference to its direction relative to the earth’s true North Pole…or in a True direction.

Need to Know

Direction is the relationship of one position with respect to another position. Direction on a chart is always measured in degrees (TRUE, MAGNETIC, or PER ship’s steering MAGNETIC COMPASS or PMC).

Only take True readings from the chart and back to the chart. Never, ever inter-mix true and magnetic readings in respect to ship’s heading and course.

When taking readings to or from the compass rose, always use the sharp, finely tipped point on either leg of the dividers as a pivot point at the center mark of the rose. Holding a rule firmly against this pivot point provides for the most accurate positioning and reading of the rule’s straight edge on the degree ring of the compass rose.

Learning Exercise: Direction

In the following problems, now find the course heading in True degrees. Be careful when determining direction that you read the true compass rose in the correct direction. Please don’t remove the solutions from the chart, as they will be used for following problem sets.

1. From LAT 037º 07.5’ N LON 075º 39.1’ W to 36º 57.0’ N LON 075º 41.0’ W

- ____________ degrees True

2. From 37º 01.6’ N 075º 31.7’ W to 36º 57.0’ N 075º 41.0’ W

- ____________ degrees True

3. From 37º 00.5’ N 075º 43.8’ W to 37º 00.0’ N 075º 30.0’ W

- ____________ degrees True

4. From Wolf Trap Light to New Point Comfort Spit Light “2”

- ____________ degrees True

5. From Chesapeake Light to Buoy “NCA”

- ____________ degrees True


1. 188º T
2. 238º T
3. 092º T
4. 211º T
5. 313º T

Lesson 8: Measuring Distance

At sea, the distance between two points is measured in nautical miles (nm) not statute miles. The ancient Roman’s placed a statute at the start and finish of one thousand (1,000 or a “mil”, hence the term “mile”, a statute mile), double strides of marching Centurions. As recorded, a full Centurion double stride was considered to be about 63 inches or five (5) feet three (3) inches in length. Given this fact, one-thousand Centurion double strides amounted to about 5,250 feet in distance. Approximately equal to our modern statute mile of 5,280 feet (.87 of a nautical mile). Unlike the Roman’s statute mile, a nautical mile is not dependent on a Centurion stride. It’s based on earth’s girth at its equator not its poles, (East to West = 7,925.77sm, North to South = 7,899.09sm).

The distance or length of one (1) degree of longitude measured at the earth’s equator (and only at the equator) or 1/360th of the distance of the earth’s circumference (21,600nm) is 60 nautical miles. Therefore 1/60th of a degree or one (1) minute of longitude equals one (1) nautical mile (1nm = 6,076 feet – which is 1.15 times longer than a statute mile). At the earth’s equator, the planet’s east-west circumference is more-or-less equal to its north-south circumference. Therefore, in the real world and only at the earth’s equator does the length of one (1) degree longitude (more or less) equal the length of one (1) nautical mile. Traveling north or south away from the earth’s equator, the east-west distance between lines of longitude eventually decrease to zero as they converge at the poles. Because meridians of longitude are not parallel lines, they do not lend themselves to accurate distance measurements. Lines of latitude, are commonly referred to as parallels of latitude and therefore do not converge at the earth’s poles or anywhere else. Latitude is our guide to accurate distance measurements.

Since most nautical charts are based on Mercator projection, with its inherent distortion of all earthly surface features, we do not use degrees of longitude for distance measurements.

- To measure distance in nautical miles: Use the vertical margins ONLY, do not use the top or bottom horizontal margins. One (1) nautical mile equals one (1) minute on the vertical margins.

Ø One degree of indicated latitude is equal to sixty (60) nautical miles in distance. Each degree is divided into sixty (60) minutes, with each minute equal in distance to one (1) nautical mile. As already mentioned, each minute is then divided into tenths. Each tenth of a minute is equal to 1/10th of a nautical mile.

Learning Exercise: Distance Measurement

Using your dividers – measure the distance in nautical miles (nm) between the following positions – use your Light List to find the following charted objects.

1. What is the distance from Cape Henry Light to Cape Charles Light?

A. 12.1nm
B. 12.4nm
C. 12.8nm
D. 13.0nm

2. What is the distance from Chesapeake Channel Y “NCA” Whistle buoy to Chesapeake Light?

A. 5.9nm
B. 6.5nm
C. 6.8nm
D. 7.1nm

3. What is the distance from New Point Comfort Spit Light “2” to York River Entrance Channel R “18” QR Gong buoy?

A. 3.9nm
B. 4.3nm
C. 4.5nm
D. 4.7nm

4. What is the distance from Horn Harbor Entrance Light “HH” to Wolf Trap Light?

A. 4.0nm
B. 4.3nm
C. 4.5nm
D. 4.7nm

5. What is the distance from abeam of Trestle “A” and Trestle “B” of the Chesapeake Bay Bridge and Tunnel to GR “CBJ” Gong buoy?

A. 7.7nm
B. 7.4nm
C. 7.2nm
D. 7.0nm

Answers: 1. C 2. B 3. D 4.C 5.A

Lesson 7: Navigation

Navigation refers to the science by which a vessel’s location, course, and destination at sea can be determined and plotted. This allows the navigator to avoid obstacles (in known positions but perhaps not visible), and the vessel’s course to be known and set. At the end of the day, there are four methods of navigation.

Celestial – using the sun, stars, and the moon in determining the vessel’s position.

Terrestrial (Piloting) – using earth based reference points, such as aids to navigation, landmarks, and or depth sounding to determine position.

Deductive (Dead) Reckoning – using a vessel’s speed, course, time, and previous known positions to deduce an approximate position.

Electronic – using GPS, LORAN, RADAR and other electronic instruments to determine position.

Tuesday, September 23, 2008

Maritime Licensing Blog....

Licensed mariner ? - click here for latest license information.........


Seattle AB and Master 200 Classes....

Zenith Maritime is offering two new USCG approved merchant mariner license trainings starting this fall at Fishermen's Terminal - Seattle. The first training is a 56-hour AB Unlimited course (written exams and knot tying) running from December 1 to 12, 2008 plus a 112-hour Master 200 ton (near coastal) course - February 9 to 27, 2009. Both courses are weekday classes (M-F 8am to 5pm) and will be instructed by Mr. William Anderson. Captain Anderson is a graduate of California Maritime Academy and holds first class pilot licenses for Puget Sound and Western Alaska. For more information - please contact John Baird at 360.471.6148 or john@zenithmaritime.com

ATONS Quiz...

A Short Quiz

1. A buoy having red (top) and green (bottom) horizontal bands would have the light characteristics of:
A-Interrupted quick flashing.
B-Composite group flashing (2+1).
C-Morse (A).
D-Quick flashing.

2. A safe water mark may be:
A-Vertically red and white striped.
B-Spherical top mark.
C-Showing a white light.
D-All of the above.

3. Which navigational mark may only be lettered?
A-An unlighted, green, can buoy.
B-A spherical buoy.
C-A red buoy.
D-A port side day-shape.

4.You are heading out to sea in a buoyed channel and see a quick flashing green light on a buoy ahead of you. In US waters, you should leave the buoy:
A-Well clear on either side.
B-About 50 yards off on either side.
C-To port.
D-To starboard.

5. A buoy marking a wreck will show a(n):
A-White light FL (2) and a top-mark of two black spheres.
B-Occulting green light and may be lettered.
C-Yellow light and will be numbered.
D-Continuous quick white light and may be numbered.

6. You are approaching a swing bridge at night. You will know that the bridge is open for river traffic when:
A-The fixed, green light starts to flash.
B-The amber light changes to green.
C-The red light is extinguished.
D-The red light changes to green.

7. When you are steering on a pair of range lights and find the upper light is above the lower light you should:
A-Come left.
B-Come right.
C-Continue on the present course.
D-Wait until the lights are no longer in a vertical line.

8. When displayed under the a single-span fixed bridge, red lights indicate:
A-The channel boundaries.
B-That all vessels must stop.
C-The bridge is about to open.
D-That traffic is approaching from the other side.

9. When navigating a vessel, you:
A-Can always rely on a buoy to be on station.
B-Can always rely on a buoy to show proper light characteristics.
C-Should assume a wreck buoy is directly over the wreck.
D-Should never rely on a floating aid to maintain its exact position.

10. A lighthouse can be identified by its:
A-Painted color.
B-Light color and phase characteristics.
C-Type of structure.
D-All of the above.

1.B 6. D
2. D 7. C
3. B 8. A
4. D 9. D
5. A 10. D

Bayliner Buccaneer Websites....

I was just on Capt. Rodriguez's Bitterend blog....if interested in Bayliner's sailboats visit -




Double Clamped....

One of the most frequent marine survey recommendations (see ABYC Standards and Recommended Practices) made regards the lack of having two (2) all stainless steel hose clamps at all below-the-water line hose connection. You might have the best marine grade hose clamped by either a plain steel clamp or a stainless steel band clamp with a pot-metal worm screw....either way - failure could cause accidental flooding - sinking.

Monday, September 22, 2008

Compression Post and Keel Step.....

I just finished a survey of a Catalina Capri 26 (wing keel) which had a deck stepped mast and compression post. Usually, boat builders generally (somehow) conceal the step or foundation at the keel which supports the compression post...in this particular boat - the step was partially visible (in the bilge) which allowed for a reasonable inspection with a fairly surprising discovery. The wood step has been painted on the lower portion (which is good construction practice) but the upper section still just raw wood - which could be affected by any water in the bilge.

USCG License Prep and Evaluation Services....

Norleen Schumer (former Assistant Chief REC-Puget Sound) offers mariners license consulting services from her office near Port Orchard, Washington which include application preparation and pre-evaluation for all licenses and MMDs.


360-447-8328 8 AM to 4 PM M-F Pacific Time
360-616-2730 FAX

Saturday, September 20, 2008

That's a Wrap.....

Every fall - fish nets fill the Lake Washington Ship Canal (what ever happened to 72 COLREGS Rule 9) --- here's a Owens Aruba which got messed up in the nets...wrapping the net between the prop shafts pulling them together and forward which rolled and cupped the underbody planking eventually breaking the stringer which the port side prop strut is hung from.

Friday, September 19, 2008

Lesson 6: Chart Work

-The rules for extracting and plotting a position are simple. Here they are:

- To find the latitude of a position: Use the vertical margins (scale), left or right. They are marked in units of degrees, minutes, and tenths of a minute, and sometimes in seconds (6 seconds = 1/10th of a minute).

- To find longitude of a position: Use the horizontal margins, top or bottom. They are also marked in degrees, minutes, and tenths of a minute, and sometimes in seconds.

Learning Exercise: Finding Latitude and Longitude

Extract from the Chart 12221 TR the latitude and longitude of the lights listed below (use the supplied Light List for general location only).

Cape Charles Light (LL 345)

- Latitude _________________

- Longitude_________________

Wolf Trap Light (LL 6800)

- Latitude _________________

- Longitude_________________

York River Entrance Channel Lighted Gong Buoy “2” (LL 12130)

- Latitude _________________

- Longitude_________________

Chesapeake Light (LL 355)

- Latitude _________________

- Longitude_________________

Rudee Inlet Lighted Whistle Buoy “RI” (LL 425)

- Latitude _________________

- Longitude_________________


1. LAT 37 º 07.4’ N LON 075 º 54.4’ W
2. LAT 37 º 23.4’ N LON 076 º 11.4’ W
3. LAT 37 º 07.4’ N LON 076 º 09.2’ W
4. LAT 36 º 54.3’ N LON 075 º 42.8’ W
5. LAT 36 º 50.0’ N LON 075 º 56.8’ W

Learning Exercise: Plotting Latitude and Longitude

Plot the following positions on the chart and identify the following lights-buoys.

LAT 37º 20.2’ N LON 076º 15.1’ W

- Object at above position:_______________________________

LAT 37º 17.8’ N LON 076º 15.7’ W

- Object at above position:_______________________________

LAT 37º 00.1’ N LON 076º 17.9’ W

- Object at above position:_______________________________

LAT 36º 55.6’ N LON 76º 00.4’ W

- Object at above position:_______________________________

LAT 37º 21.8’ N LON 075º 43.7’ W

- Object at above position:_______________________________

1. Horn Harbor Entrance Light “HH”
2. New Point Comfort Spit Light “2”
3. Thimble Shoal Lighted Buoy “22”
4. Cape Henry Light
5. Great Machipongo Light “5”

Charting in Seattle........

Mariners hard at work in my current Seattle M100 class......

Lesson 5: Latitude and Longitude

Need to Know

Lines on the surface of the earth, running from the true south-pole to the true north-pole are called Meridians of Longitude.

Lines on the surface of the earth which are parallel to the equatorial plane are called Parallels of Latitude.

Both latitude and longitude are needed to specify a single point (nothing more than a grid system).

There are only ninety (90) degrees of either north or south latitude. There are only one hundred eighty (180) degrees of either east or west longitude for a combined total of three hundred and sixty (360) degrees.

On a nautical chart, degrees of latitude are expressed vertically in a north-south direction and likewise, degrees of longitude are expressed horizontally in an east-west direction.

Reference to a recorded position or fix should be labeled either N or S for North or South latitude and E or W for East or West longitude. Directional labels are not interchangeable between latitude and longitude.

An unknown position on a chart is determined or taken from the chart by extending a horizontal line and a vertical line (forming the legs of a right angle) from a position on the chart’s towards its respective scales (either latitude and longitude) printed on the chart’s margins. At the point which each line precisely intersects on each scale, degrees, minutes, and seconds or tenths of a minute (DDDº MM.TT’) of both latitude and longitude can be read and recorded.

Likewise, a recorded or known position (fix) is indicated in degrees, minutes, and tenths of a minute (DDDº MM.TH’) of latitude and longitude and can be taken to the chart or plotted by simply extending a horizontal line from the indicated point on the latitude scale and a line vertically from the indicated point on the longitude scale. The intersection of the resulting right angle indicates a precise visual representation of a real-world position on the chart’s printed surface.

The earth takes 23 hours, 56 minutes, and 4.09054 seconds (side real time) to make one complete rotation (24 hour average or meantime). Therefore 360 degrees divided by 24 means that 1 (one) hour = 15 degrees = 900 nm.

Day Light saving time borrows the next time zone to the east.

Thursday, September 18, 2008

Lesson 4: Mercator Charts

No chart or map of the earth is accurate. As mentioned above, the very attempt to portray a portion of a sphere (such as the earth) on a flat surface is difficult at best. All charts attempt to be correct in some detail or at some points but are in error at others. The chart most used for coastal and inland marine navigation is the Mercator chart. Mercator's projection has some evident distortions as to shape, area and scale but it has one feature mariners prize well above all others - a line of bearing on the chart is equal to the compass course between two points. Most charts are "projections" in that they are supposed to represent on a flat plane a projection of a point on the surface of the earth.

Charts attempt to emphasize one of the following qualities:

- Preservation of area
- Preservation of shape
- Preservation of scale
- Preservation of bearing

To achieve any one of these qualities the rest must be, to some degree, sacrificed.

In the Mercator projection, preservation of bearing is all important and scale, shape and area are progressively distorted as the latitude increases. Therefore, charts using Mercator projections, all Great Circles are arcs with the exception of the equator and lines of longitude.

Mercator projections are "cylindrical" projections insofar as they are derived by imagining a large sheet of paper wrapped about the earth in the form of a cylinder. For this example we will imagine this sheet touching the earth only at the equator. Then, from the center of the earth, we will draw lines through features on the surface of the globe and continue those lines until they strike the paper cylinder.

It is easy to see that the poles can never be represented on such a chart and that the distortions inherent at higher latitudes make the area and shapes of such features as Greenland wholly untenable. Mercator's projection is not as simple as described above but a mathematically developed projection so as to preserve a specific ratio between the latitude and longitude.
As mentioned previously the Mercator chart allows a loxodrome - or line of constant bearing - to be drawn on it as a straight line between two points. Such a line cuts every line of longitude at the same angle.

Another nautical chart used by mariners is the Gnomonic projection. This chart allows Great Circles to be drawn as straight lines. It is even more complicated where bearings must be calculated for every position of the chart as no compass rose can be shown on such a chart - except for one particular point.

Gnomonic projections, or variants thereof, are frequently used to depict the earth’s polar areas as these areas lend themselves well to such projections.

Need To Know

A nautical chart is a mariner’s most important tool.
Select a chart (projection, scope, and scale) which meets your safe navigational and sailing needs.

Sailing Chart - scales 1:600,000 and smaller, are for use in fixing the vessel’s position as she approaches the coast from the open ocean, or for sailing between distant coastwise ports.
General Chart - scales 1:150,000 to 1:600,000 are for inshore navigation leading to bays and harbors of considerable width and for navigating large inland waterways.
Coast Chart - scales 1:50,000 to 1:150,000 used for inshore coastwise navigation. Shows shoals and reef areas, large inland waterways, and larger bays and harbor entrances.
Harbor Chart - scales larger than 1:50,000 are for harbors, anchorage areas, and the smaller waterways.
Special Chart - various scales, covers the Intra-Coastal Waterway (ICW) and miscellaneous Small Craft (SC) areas.

Charts must be studied and understood before using. NOAA Chart No. 1 is a must.

Vertical printing on charts which refer to features which are dry at high water.

Slanted printing on charts which refer to aids to navigation and features which are submerged at high water.

Chart legends which indicate a conspicuous landmark is printed in CAPITAL LETTERS.

The term RACON besides an illustration on a chart would mean a Radar transponder beacon

The Coast Pilot (published by National Ocean Service - NOS and NOAA) (Sailing Directions in foreign waters) and The Light List (List of Lights in foreign waters) are to be used with charts.
Each publication contains a wealth of important information for both navigators and mariners. Each publication starts with general information such as aids to navigation, landmarks, weather, radiotelephone, navigation regulations, VTS, and emergency procedures. Generally information that cannot be shown on a chart.

Notice to Mariners – The USCG on a weekly basis provides updates and corrections to navigational charts and related publications.

Pilot Charts – Ocean chart presenting historical weather, wind, current (ocean currents, not tidal currents), and sea conditions by month allowing a navigator to quickly determine the shortest and safest route.

Tide and Current Tables – Publications predicting regional and local tide and currents (tide, time, height, direction, and velocity).

Chart Correction System Background Information The Chart/Publication Correction Record Card System is used to conserve nautical charts and publications and to reduce the amount of chart correction work aboard ship. The Notice to Mariners, Local Notice to Mariners, Summary of Corrections, NAVTEX and SafetyNet are considered component parts of the system. A record must be maintained for Notice to Mariners corrections to all charts and publications carried aboard, with actual corrections being made on all charts and publications before they are used for navigational purposes. Never use an uncorrected chart for navigation purposes.

Lesson 3: ATONS

ATONS: Need To Know

The United States utilizes the IALA (International Association of Lighthouse Authorities) Region B system running in a clockwise direction around the United States. This means south along the Atlantic (east) coast, west across the Gulf (coast) of Mexico, north on the Mississippi River (Western Rivers), and north along the Pacific (west) coast. This is known as arbitrary assumption.
A lateral aid’s meaning or significance is denoted by its color and shape.
IALA Region B means keeping the red buoys to starboard when returning from sea. Red and Green navigation aids convey lateral significance. Red Right Returning
Red aids are marked with even numbers and green aids have odd numbers. Both red and green aids grow in numerical value when viewed returning from sea (i.e., red aids 2, 4, 6, 8…etc., green aids 1, 3, 5, 7…etc.)
Preferred channel aids with both red and green horizontal color bands have lateral significance. They indicate the presence and direction of a primary channel by observing the aid’s top most color band as you would with either an all red or all green aid. The lower color band indicates the presence of a secondary channel. Flash characteristic is Group Composite Flash (2 + 1) or two channels pick one
Red or green aids are often fitted with a quick flashing light to indicate a bend or turn in a channel or fairway.
Yellow aids and buoys indicate a special situation and never convey lateral significance. They (yellow aids) indicate the presence of a VTS, the ICW, fish traps, etc. Yellow marks indicate a special situation
Red and White aids are called safe water buoys and have no lateral significance. These sometimes indicate the start-end of something, such as a buoyed channel, off-shore approach points and can be passed on either side. Sea buoys
Red and Black buoys indicate an isolated danger immediately below or adjacent to the aid and have no lateral significance. Always approach with due caution and attention. Black Balls of Death
Diamond shaped, checkered aids convey no lateral significance they convey information regarding location.
White aids with an orange boarder with diamond, square, or circle in shapes, have no lateral significance. These convey important information such as shallow water, reduced speed zones, or other regulatory information.
Range markers are used in pairs to indicate the center or safe water of a fairway or channel when vertically aligned.
Light Color - Red, green, yellow, and or white. If the light color is not designated on the chart, the color is white. See Light List.
Light Phase Characteristics – Light sequences or pattern of light shown within one complete cycle of the light. See Light List.
Light Period – The length of time required for the light to progress through one complete cycle of changes. See Light List.
Buoys - Buoys can be lighted or unlighted and are attached to a sinker which keeps it in its charted or reported position. A buoy’s color and shape are significant. Charts will show a buoy with its color, shape and light characteristic. Use the Notice to Mariners to update charts on a regular basis….a chart correction card shows the correction dates per chart.
Lighthouses - These are major structures with distinctive color and light schemes (or sequences). Many lighthouses also have sound signals.
Daybeacons - These are structures similar to beacons, except they are unlighted and are usually single-pile.
Minor Lights and Beacons - These are much smaller than lighthouses, but also give light signals. They are single or multi-pile structures, although sometimes can be also skeleton or masonry towers. They have dayboards which are plywood boards with significant shapes and colors, numbers or letters, and a reflective tape around them.

Light Phase Characteristic
Fixed (F)
Flashing (Fl)
Quick Flashing (Qk Fl)
Interrupted Quick Flashing (I Qk Fl)
Group Flashing (Gp Fl)
Morse “A” (Mo (A)) Equal Interval (E Int) or Isophase (Iso)
Occulting (Occ)
Group Occulting (Gp Occ)

Real Mariner Speak...

Ted Lones, (Zenith instructor - Denver) sent me this piece of work....thanks!

Set up: About a year ago an oil tanker off the coast of Australia split in half, spilling thousands of gallons of crude oil into the sea. This guy - Collins, a senator in the Australian Parliament, appeared on a TV news program and used some real sailor language...

Galvanic Action in Wood Vessels

So what this galvanic stuff all about?

When you have dis-similar metals in wet (salt water) soaked wood - you set up a galvanic cell or a battery. When, due from various reasons, the current potential reaches (based on my observations) about 350 - 400mv, then the galvanic current creates alkaline substances in the wood which break-down the glue (ie., lignins - an organic polymer) which keeps the wood togther.

The pictures are from a recent survey of a Sabercraft where galvanic current (from a transom mounted plate zinc) has damaged the plywood surrounding the plate's thru-hull fasteners.

Ballard Salmon Jump

It's that time of year - salmon jumping in the locks and Lake Washington Ship Canal

Wednesday, September 17, 2008

Today's Schedule....

0430 - Shower
0705 - West Seattle - Southworth (Kitsap Peninsula) ferry
0900 - Port Orchard, Washington - Docksides: survey Sabercraft 2600 condition and value - underbody and fastener report -
1455 - Southworth - West Seattle ferry
1600 - Decompress - get ready for license class
1730 - 2200 - M100 class at Fishermen's Terminal - Seattle
2300 - Dinner - crash and burn.........

License Class...Lesson 2

What’s an USCG Licensed Operator of Uninspected Vessels?

If a vessel carries passengers for hire, the operator must hold a current USCG license. The original license must be onboard when sailing with passengers (even with 1 passenger). A copy of the current license is not permitted. Upon expiration of the current license (valid for 5-years), the mariner must show 360-days of seatime accrued during the current issue of the license in order to renew without testing. Once expired, there is no grace period in which a mariner can operate under the authority of his license. This is a one-year grace period for license renewal only. During this 12-month period a mariner can renew without having to re-take all of the examinations or tests. Operating a vessel with an expired license can subject a mariner to a civil penalty and could impact the ability of the mariner to renew his license.

The USCG issues merchant mariners licenses to those mariners who have duly examined and qualified to hold an Operator or Master’s license. There are three main areas to be dealt with in the licensing process. First, are the basic requirements which must be met, these are:

Minimum age 18 years.
Proof of US citizenship or legal resident
Three signed character references attesting to personal character and responsibility.
Current within 12 months First Aid/CPR card.
Current within 12 months medical examination.
Current within 6 months USCG approved drug screening.
Birth certificate.
Current photo identification card.
Original Social Security card.

In addition, each mariner must demonstrate on the water experience or seatime. For an OUPV license, the USCG allows mariners to do this through a process call self-certification. That is, the mariner is required to document how many days of experience (one day equals 4-hours underway during a 24-hour period of time) while underway for each month, year, and boat for which time is claimed. In addition, USCG requires proof of ownership or use of the vessel to support any and all time claimed. A pre-existing The seatime requirements for Inland, Near-Coastal, and Great Lakes routing are as follows.

Inland Routes: 360 days on Inland waters, (1 day equals 4 plus hours underway in a 24 hour period) counted from your 15th birthday.
Of the 360 days, 90 days of those must be within the last 3 years.

In addition for Near-Coastal and Great Lakes endorsements:

Near Coastal endorsement requires 90 days of the 360 days in near coastal waters. Allows operation of un-inspected vessels up to 100 miles off shore.
Great Lakes endorsement, allows operations on the Great Lakes but requires 90 days of the 360 to be on the Great Lakes.

The last requirement is to pass four written examinations which deal with chart reading, piloting, tides-currents, weather, compass, navigation rules, rules-regulations concerning passenger boat operations, seamanship – marlinspike, pollution, safety, lifesaving equipment, boat handling-anchoring, radiotelephone, and small marine engines. All examinations are in written format with multiple choice answers. Each mariner has the opportunity to re-exam (up to two times) in each of the following four subject areas:

· Piloting (Charting) – 10 questions, 70% correct to pass.
· Navigation General – 20 questions, 70% correct to pass.
· Navigation Rules (COLREGS – US Inland) – 30 questions, 90% correct to pass.
· Deck General and Safety + Environmental – 70 questions, 70% correct to pass.


The waters of the United States and its territories are marked to assist navigation by the U.S. Aids to Navigation System (ATONS). This system employs a simple arrangement of color, shapes, numbers, and light characteristics to mark navigable channels, waterways, and obstructions adjacent to these.

Aids to Navigation can provide a boater with the same type of information that (car) drivers get from street signs, stop signs, road barriers, detours, and traffic lights. These aids may be anything from lighthouses to minor lights, day beacons, range lights, and sound signals, to lighted or unlighted buoys. Each has a purpose and helps in determining location, getting from one place to another or staying out of danger. The goal of the U.S. Aids to Navigation System is to promote safe navigation on the waterway.

The U.S. Aids to Navigation System is intended for use with Nautical Charts. Charts are one of the most important tools used by boaters for planning trips and safely navigating waterways. Charts show the nature and shape of the coast, buoys, and beacons, depth of water, land features, directional information, marine hazards, and other pertinent information.
The primary components of the U.S. Aids to Navigation System are beacons and buoys.
Beacons are aids to navigation structures that are permanently fixed to the earth’s surface. The range from lighthouses to small, single-pile structures and may be located on land or in the water. Lighted beacons are called lights; unlighted beacons are called day-beacons. Beacons exhibit a day-mark to make them readily visible and easily identifiable against background conditions. Generally, the day-mark conveys to the boater, during daylight hours, the same significance as does the aid’s light or reflector at night.

Buoys are floating aids that come in many shapes and sizes. They are moored to the seabed by concrete sinkers with chain or synthetic rope moorings of various lengths connected to the buoy’s body. They are intended to convey information to the boater by their color and shape, by the characteristics of visible or audible signal, or a combination of two or more such features.

Sail Boat Standing Rig....What's Wrong with this Picture?

Tuesday, September 16, 2008

Galvanic Current in Wood Vessels

Had a couple of questions regarding galvanic current in wood which causes alloy wastage in metal fasteners and weakened wood structures... the attached pictures are of a Pacemaker which I recently surveyed where the builder installed a copper strap (on top of the keel) running aft from the machinery space. The problem is that in doing so...nearly 50 years later - the current flowing through this strap, the wood, keel bolts, underwater hardware et al - eventually damaged the wood keel which it was attached - thus producing fuzzy, cracked, and soft wood - sometimes covered with a fine white powder which is sodium hydroxide (usually next to a fastener or thru-hull fitting). The solution here....remove strap, clean - treat wood surfaces with distilled white vinegar (and maybe Restore-It), and monitor. The concern here is...if the damaged wood weakens the garboard seam there could be mass problemas - especially in this instance where the keel isn't particularly husky in the first place and is substantially reduced at the keel cut-a-way at the stern. The take-away wisdom here (at least in my humble opinion), is not to common bond underwater hardware in a wood boat.