Monday, March 31, 2008

406 GPS Personal Locator Beacon

The 406 GPS Personal Locator Beacon (PLB) is designed to be manually deployed and activated. It is only to be activated when all other means of self-rescue have been exhausted. When activated the PLB tells Search and Rescue who you are, where you are, and that you are facing a life threatening situation.

Activate - To activate the PLB in a distress situation, unfasten the antenna from the case and move it into the upright position. Depress the ON/OFF button for 1 full second. Your PLB is now activated. While transmitting your distress signal, the red LED will flash once every 2 seconds alerting you that your PLB is transmitting. An additional BEEP will sound every time your PLB sends off a burst to the satellites (roughly every 50 seconds).

Activation with GPS - This PLB is equipped with an internal GPS receiver. Once activated the GPS engine will start up and search to find your LAT/LON and incorporate it into your 406 MHz signal. As soon as the GPS receiver acquires good positioning data the red LED will stop blinking and the green LED will begin flashing once every 2 seconds.

Once good global positioning data has been obtained, the GPS receiver waits for 20 minutes before looking for new positioning data again. If for any reason a time period of 4 hours passes without the GPS receiver being able to update the last good set of GPS coordinates, the 406 message being transmitted will revert to the default data. At this point the green LED will stop blinking and the red LED will flash once every 2 seconds until new GPS coordinates have been obtained.

THE SEARCH AND RESCUE SYSTEM - The PLB provides a distress message on 406 MHz to satellites of the COSPAS-SARSAT network and to the GEOSAR network that includes GPS latitude and longitude coordinates when GPS data is present.

The message transmitted is unique for each PLB, which provides identification of the transmitter through computer access of registration files maintained by the National Oceanic and Atmospheric Administration. Remember, if your PLB is not registered, Search and Rescue (SAR) Authorities do not know who you are, or how to contact anyone who might know anything about your situation.

Once the signal (406 MHz) is relayed through the LEOSAR and/or GEOSAR network, SAR forces determine who is closest, and then track the signal using the 121.5 MHz homing frequency for intermediate and short-range location.

This satellite system has no Doppler capabilities at 406 MHz, but will relay the distress alert to any of the LUT stations. When there is GPS data included in the distress message, SAR authorities instantly know your location to within 110 yards (100 m). This speeds up the reaction time by not having to wait for one of the LEOSAR satellite to pass overhead.

Because most of the search and rescue forces presently are not equipped to home in on the 406 MHz Satellite PLB signal, homing must be accomplished at 121.5 MHz.

Global Positioning System (GPS) - The GPS system is a satellite group that enables a GPS receiver to determine its exact position to within 110 yards (100 m) anywhere on Earth. With a minimum of 24 GPS satellites orbiting the Earth at an altitude of approximately 11,000 miles they provide users with accurate information on position, velocity, and time anywhere in the world and in all weather conditions. The PLB stores this data into its distress transmission allowing search and rescue forces to narrow the search into a very small area and minimize the resources required and dramatically increases the effectiveness of the overall operation.

Satellite Detection - The PLB transmits to the satellite portion of the COSPAS-SARSAT System. COSPAS-SARSAT is an international system that uses Russian Federation and United States low altitude, near-polar orbiting satellites (LEOSAR) that assist in detecting and locating activated 121.5/243 MHz beacons and 406 MHz Satellite beacons.

COSPAS and SARSAT satellites receive distress signals from PLBs transmitting on the frequency of 406 MHz. The COSPAS-SARSAT 406 MHz beacon signal consists of a transmission of non-modulated carriers followed by a digital message format that provides identification data. The 406 MHz system uses Satellite-borne equipment to measure and store the Doppler-shifted frequency along with the beacons digital data message and time of measurement. This information is transmitted in real time to an earth station called the Local User Terminal (LUT), which may be within the view of the satellite, as well as being stored for later transmission to other LUTs.

The LUT processes the Doppler-shifted signal from the LEOSAR and determines the location of the beacon; then the LUT relays the position of the distress to a Mission Control Center (MCC) where the distress alert and location information is immediately forwarded to an appropriate Rescue Coordination Center (RCC).

Sunday, March 30, 2008

Bottom Paint (Small Boats)

There are three (3) basic causes for bottom fouling:
Animal Fouling.
1. Critters such as barnacles and zebra mussels find boats, sitting static in their slips, an ideal surface upon which to attach themselves and multiply.
2. Plant Fouling
Just like barnacles, weeds also attach themselves to static surfaces. This occurs most frequently near the waterline where sunlight abounds.
3. Slime Fouling
This mess is created by algae that settle into a gooey medium and happily reproduces. An algae colony soon attracts other organisms which, combined with the slime, makes for a really ugly and slow boat bottom.
The best answer to this problem is antifouling bottom paint. These paints reduce or eliminate any marine growth that develops on your boat's underwater surfaces. Antifouling paints do this by using biocides (chemicals) that slowly release during the season to repel underwater aquatic life. Most of the antifouling paints use cuprous oxide (copper) combined with other mysterious stuff to get the job done.
There are a couple of basic types of antifouling paints. Each one has its pluses and minuses.
Ablative Antifouling Paint
This paint wears down much like a bar of soap as your boat moves through the water. As a result, fresh layers of biocide are constantly being exposed throughout the boating season. This type of paint works well in high marine growth areas and continues to work even with multiple haul-outs, just as long as any of the biocide remains. Because of the way it works, putting on 2 or 3 coats of paint initially is a good idea.
Another plus is that you can apply ablative paint over most other antifouling paints. The downside is that because these paints are relatively soft, you will be removing bottom paint with each brush stroke every time you scrub your bottom or waterline. Also, it wears away quickly on high drag areas such as rudders or other bottom appendages. Likewise, trailer rollers and bunks grind it off in a big hurry.
Hard Antifouling Paint
If you and your boat like to go "warp factor six with your hair on fire," then a hard antifouling paint would be a likely choice. This paint starts leaching out biocide upon contact with the water to prevent marine growth. However, after a period of time (say 6 months to a year), the paint starts to run out of "ammo" and becomes much less effective than it was when first applied.
In addition, hard antifouling paint will build up. Because the medium that holds the biocide does not wear off, it needs to be periodically, physically removed to prevent excessive paint build-up on the bottom. Some hard antifouling paints have Teflon added to further reduce surface friction.
Those of you with aluminum hulls should heed this caution. DO NOT put bottom paint containing copper directly over aluminum. If you let these two (2) dissimilar metals come into contact with each other and put them into water, you will have just built yourself a large battery! Immediately on contact with water, a process known as electrolysis corrosion will set in.

Small Boats (Crossing a Bar)

" The boat above made it"

" This boat did not"

Most navigable entrances have a bar, A BAR ENTRANCE CAN BE VERY DANGEROUS. Whenever a bar is to be crossed extra precautions need to be taken to minimise the risk to your boat and crew. Regardless of the vessel type the conditions at the bar must be examined before committing the craft to either enter or exit. The combined effects of tide, swell and wind need to
be assessed. A run out tide against either wind and / or swell can produce waves so big that an entry or exit is a bad idea, even when there are just small waves. Waves not running perpendicular to the required course can also make the situation worse. A narrow entry / exit channel gives less room to manoeuvre and smaller margins for errors in judgment. Not being familiar by the skipper and crew also makes for higher risks. Sometimes familiarity can be detrimental to making good decisions because of overconfidence and an attitude that the home bar has no fears. There will usually be a strong desire among the crew to either get home or get out which could easily be detrimental to making wise decisions in marginal conditions. IF IN DOUBT STAY OUT DO NOT ATTEMPT TO CROSS. Some precautions should be taken when crossing a bar.

Standard Precautions :
Check appropriate weather forecasts.
Call the Coast Guard for the latest bar conditions and tell them your intentions.
Secure all loose items.
Have everybody don life jackets.
Close and secure all hatches.
Brief all crew on emergency drills.
Determine the wave pattern before committing the boat.
Don't cross a bar with another boat.
Do not cross if the bar is breaking.
Spend as little time as possible on or near a bar.
Cross about 1-2 hours before high tide, but keep in mind this can very.
Before crossing try and time the series of bigger waves.

General Considerations:
There are two basic things, the entry and the exit, and there are quite marked differences in the techniques that should be used for a safe bar crossing. An important technique common to all craft is to keep the boat perpendicular to the wave fronts, especially when the waves are either large or steep. For an Exit the main decision is whether the boat can be controlled as it travels against and through the waves, especially as it falls off the top into the trough. Two conflicting requirements arise, the need to have the boat go over each crest slowly against the need to minimise the time spent on the bar. Judgment and experience are a must. Further consideration becomes necessary in marginal conditions,for the return will the bar allow a safe crossing and, if not, what are your other choices. Can the boat be positioned safely close enough to the bar to observe the wave pattern on and just outside the bar? Is the navigable channel wide enough to allow the boat to travel at right angles to the wave fronts?

For an Entry the technique depends primarily on the type of craft and whether it has the capability to travel at or above the speed of the waves. This can usually be achieved in runabouts, and in most other powered craft capable of 15Kts or better. Such craft should be held on the back of the wave once committed, using extreme caution to stop the boat getting on the forward face of the wave. A sailing vessel with a fixed deep keel will normally not be able to keep pace with a wave. These vessels should use most or all power to minimise the time spent in the danger zone and reduce the risk of broaching. When on the face of the wave the rudder use becomes critical to keep the boat as straight as possible and perpendicular to the wave. This problem for slower boats usually makes an entry much more hazardous than an exit. All skippers should only commit the boat at the end of the large waves of a set, in marginal conditions this will involve considerable time holding the boat in a safe position from where the wave pattern can be best seen.

Saturday, March 29, 2008

Small Boats

Discharge Current
When going ahead, the rudder is in the propeller’s discharge current. This explains the better steerage afforded by forward propulsion than by reverse, in reverse gear, not only is propeller thrust worse, but there is no discharge current flowing from the propeller over the rudder (the suction current has a much weaker effect), so there is little to amplify the rudder’s effect.

Many propellers are designed to enhance their forward propulsive efficiency. The blades are pitched, raked and cupped to give the best possible bite with the boat in forward gear, which, after all, is where the transmission spends most of its time. So, you may need to use reverse gear, perhaps when you need to stop, or to develop enough sternway to allow the rudder to steer.
However, use of reverse gear brings with it the problems of asymmetric propeller thrust and poor sternway hull dynamics. There is a bit of a balancing act required, and the internal contradiction of needing lots of power, in reverse gear, which then causes undesirable side effects, explains the limitations of sternway steerage.

Wind and Current
A boat which does handle well in reverse will also be steerable in a current. A boat crabbing in a cross current, for example, is going straight through the water. It’s just that the water itself is moving, so the boat goes diagonally over the bottom. But if the boat can steer well when making sternway in still water, it can steer equally well when making sternway in moving water.

Air in motion turns the boat, and a brisk breeze can yaw it forcefully enough that countering it with rudder or outdrive just doesn’t work. The simplest case, backing into the wind, often works well. The exact opposite, reversing with the wind, is uncontrollable in some boats, the bow blows off, and even if you can swing it back head to wind, it immediately blows off to the other side.
In between is making sternway in a beam wind. One would think that a sternway steerable boat would also do fine, but experience shows otherwise. It is a very stable vessel which allows control under this situation. For example, say you’re in a cross wind, which then blows the boat a little downwind. You would have to correct for this by turning the stern upwind. Except that now, if the blow is heavy, the bow may weathervane downwind. Even if not, the boat in a cross wind has to move diagonally through the water as well as over the bottom, so it’s usual docile sternway characteristics may be upset by not being allowed to track directly fore and aft.

Stern Way
To know and to understand the limitations of your particular boat, and to experiment, on the water, with its sternway characteristics. Spend a few minutes, now and again, doing training such as figures-of-eight. Try wide ones and tight ones, slow and fast, and in winds and currents of varying magnitude. Use power gently, and then vigorously. Try staying under power, and try coasting. You will undoubtedly gain a better feel for your boat.
There never is a conclusion to boat docking, and how much more interesting boating is as a result. In the event that any of us ever thinks we have sternway all figured out, an occasion will arise which causes us to realize that there is always more to learn.

Boat Handling (Sternway)

Backing the boat up, making sternway, is almost completely inevitable, beyond just getting into and out of our docks, however, we often have to or want to make sternway for other reasons, as part of the jockeying around for turning tight corners (backing and filling), and sometimes just because the place we want to go to is behind us, but not far enough away to justify turning the whole boat around.
Some boats are very controllable under sternway, but even these don’t behave as well as they do when making headway. At the other end of the spectrum are boats whose sternway relegate the use of reverse motion to the bare minimum possible.

Sternway hull dynamics
Part of the problem is the design of the boat. It’s built to go ahead, and to meet the water with the point of the bow, or sometimes called stem. Going astern, it doesn’t track as well, and the bow may hang off to one side, the whole boat sliding through the water diagonally. This is especially so the bigger and flatter the transom, which is exactly the opposite, to a bow. Each quarter, where the side meets the transom, may be pointy, but not at all in the right place.
So, trying to push such a structure through the water, the transom may start to slip off to one side or the other. As it does, the whole boat turns, and there are some vessels in which this cannot be counteracted no matter how you steer against it.
Sometimes the more power and more speed helps, but just as often it can make things worse. Most of us have enough sense to take off power before the boat actually starts making doughnuts in the water, but that’s just what happens, with some vessels, if you leave them in reverse for too long.

Asymmetric propeller thrust
The thrust of a propeller is often asymmetric, especially in reverse gear. This is for reasons of inclined propeller shafts, and corkscrewing propeller discharge currents, and other factors. Suffice it to say that, while the effect is almost absent in some boats, in others it can be almost overpowering, some will not back in a straight line, because of asymmetric thrust, under any conditions.
The majority of propellers are right-hand, meaning that they turn clockwise, looking forward, when in forward gear. These right-hand propellers walk the stern to port, in reverse gear. The more you understand how your boat handles, you are less likely to do anything foolish. Furthermore, the asymmetric effect can sometimes even be made to work for you, such as swinging the stern to port.

Friday, March 28, 2008

Maneuvering Your Boat

The only good way to stop your boat is to reverse the thrust direction of your propeller. This is done by first throttling your engine down to idle speed and then shifting into reverse. If you try to shift at any engine speed other than idle, you will soon destroy your gearbox. Because it takes longer to stop your boat than your car, you must approach docks and other objects slowly and, when in doubt, STOP! Never try to grab the dock with your hands and arms, or try to push off with your legs. You well get injured. When you turn the wheel on your boat, the stern starts to swing in a large arc, changing the direction of your boat. When you turn your boat, you must have enough room for your boat's stern to swing. If you try to turn too sharply when leaving the dock, the stern will swing into the dock. In a tight spot, you might want to back out that way, the stern will pull the boat away from the dock and the bow will follow.

When you stop your boat, you are still moving due to wind or current. Current can be caused by many things, such as the movement of water down a river or the rising and falling of tides. Before you try any maneuvering with you boat, check to see which way the wind is blowing by looking at the water's surface. Then stop for a few seconds to see if there is any current effecting the movement of your boat. If there is wind and/or current, try, to approach the dock with your bow into the current. This will allow you to maneuver better and also help stop your boat faster.
Maneuvering your boat takes a lot of practice. Most boaters are going to form their opinion of your boating skills by how well you handle your boat when leaving or returning to the dock. Keep in mind that nobody does it perfect every time, and people make mistakes, thats how you learn. I hope that some of these basics of boat handling are helpful.

Securing Your Boat

The only knots a dock line should have are those that you tie around cleats. The art of tying nautical knots, known as Marlinspike Seamanship, is an skill all boaters should learn.
Dock lines can be expensive, so wherever your dock line goes such as a chock or other hardware, use chafing gear around it. Chafing gear or guards can be purchased at a marine store, or you can make your own, out of an old piece of garden hose or get in good with your local fire dept. and see if you can get some old fire hose.

The diagram above is a example of how to secure your boat to a pier.

Good dock lines and good fenders are your first line of defense against hull damage. Use nylon line that's correctly sized for your boat's length and weight, and learn how to tie a proper cleat hitch.

Thursday, March 20, 2008

What AIS Broadcasts

A Class A AIS unit broadcasts the following information every 2 to 10 seconds while underway, and every 3 minutes while at anchor at a power level of 12.5 watts. The information broadcast includes:
MMSI number - unique referenceable identification
Navigation status (as defined by the COLREGS - not only are "at anchor" and "under way using engine" currently defined, but "not under command" is also currently defined)
Rate of turn - right or left, 0 to 720 degrees per minute (input from rate-of-turn indicator)
Speed over ground - 1/10 knot resolution from 0 to 102 knots
Position accuracy - differential GPS or other and an indication if (Receiver Autonomous Integrity Monitoring) RAIM processing is being used
Longitude - to 1/10000 minute and Latitude - to 1/10000 minute
Course over ground - relative to true north to 1/10th degree
True Heading - 0 to 359 degrees derived from gyro input
Time stamp - The universal time to nearest second that this information was generated
In addition, the Class A AIS unit broadcasts the following information every 6 minutes:
MMSI number - same unique identification used above, links the data above to described vessel
IMO number - unique referenceable identification (related to ship's construction)
Radio call sign - international call sign assigned to vessel, often used on voice radio
Name - Name of ship, 20 characters are provided
Type of ship/cargo - there is a table of possibilities that are available
Dimensions of ship - to nearest meter
Location on ship where reference point for position reports is located
Type of position fixing device - various options from differential GPS to undefined
Draught of ship - 1/10 meter to 25.5 meters [note "air-draught" is not provided]
Destination - 20 characters are provided
Estimated time of Arrival at destination - month, day, hour, and minute in UTC

How AIS Works

Each AIS system consists of one VHF transmitter, two VHF TDMA receivers, one VHF DSC receiver, and standard marine electronic communications links (IEC 61162/NMEA 0183) to shipboard display and sensor systems (AIS Schematic). Position and timing information is normally derived from an integral or external global navigation satellite system (GPS) receiver, including a medium frequency differential GNSS receiver for precise position in coastal and inland waters. Other information broadcast by the AIS, if available, is electronically obtained from shipboard equipment through standard marine data connections. Heading information and course and speed over ground would normally be provided by all AIS-equipped ships. Other information, such as rate of turn, angle of heel, pitch and roll, and destination and ETA could also be provided.
The AIS transponder normally works in an autonomous and continuous mode, regardless of whether it is operating in the open seas or coastal or inland areas. Transmissions use 9.6 kb GMSK FM modulation over 25 or 12.5 kHz channels using HDLC packet protocols. Although only one radio channel is necessary, each station transmits and receives over two radio channels to avoid interference problems, and to allow channels to be shifted without communications loss from other ships. The system provides for automatic contention resolution between itself and other stations, and communications integrity is maintained even in overload situations.
Each station determines its own transmission schedule (slot), based upon data link traffic history and knowledge of future actions by other stations. A position report from one AIS station fits into one of 2250 time slots established every 60 seconds. AIS stations continuously synchronize themselves to each other, to avoid overlap of slot transmissions. Slot selection by an AIS station is randomized within a defined interval, and tagged with a random timeout of between 0 and 8 frames. When a station changes its slot assignment, it pre-announces both the new location and the timeout for that location. In this way new stations, including those stations which suddenly come within radio range close to other vessels, will always be received by those vessels.

The required ship reporting capacity according to the IMO performance standard amounts to a minimum of 2000 time slots per minute, though the system provides 4500 time slots per minute. The SOTDMA broadcast mode allows the system to be overloaded by 400 to 500% through sharing of slots, and still provide nearly 100% throughput for ships closer than 8 to 10 NM to each other in a ship to ship mode. In the event of system overload, only targets further away will be subject to drop-out, in order to give preference to nearer targets that are a primary concern to ship operators. In practice, the capacity of the system is nearly unlimited, allowing for a great number of ships to be accommodated at the same time.
The system coverage range is similar to other VHF applications, essentially depending on the height of the antenna. Its propagation is slightly better than that of radar, due to the longer wavelength, so it’s possible to “see” around bends and behind islands if the land masses are not too high. A typical value to be expected at sea is nominally 20 nautical miles. With the help of repeater stations, the coverage for both ship and VTS stations can be improved considerably.
The system is backwards compatible with digital selective calling systems, allowing shore-based GMDSS systems to inexpensively establish AIS operating channels and identify and track AIS-equipped vessels, and is intended to fully replace existing DSC-based transponder systems.

Automatic Identification System

What is the Automatic Identification System (AIS)?
Picture a shipboard radar display, with overlaid electronic chart data, that includes a mark for every significant ship within radio range, each as desired with a velocity vector (indicating speed and heading). Each ship "mark" could reflect the actual size of the ship, with position to GPS or differential GPS accuracy. By "clicking" on a ship mark, you could learn the ship name, course and speed, classification, call sign, registration number, MMSI, and other information. Maneuvering information, closest point of approach (CPA), time to closest point of approach (TCPA) and other navigation information, more accurate and more timely than information available from an automatic radar plotting aid, could also be available. Display information previously available only to modern Vessel Traffic Service operations centers could now be available to every AIS-equipped vessel.
With this information, you could call any ship over VHF radiotelephone by name, rather than by "ship off my port bow" or some other imprecise means. Or you could dial it up directly using GMDSS equipment. Or you could send to the ship, or receive from it, short safety-related email messages.
The AIS is a shipboard broadcast system that acts like a transponder, operating in the VHF maritime band, that is capable of handling well over 4,500 reports per minute and updates as often as every two seconds. It uses Self-Organizing Time Division Multiple Access (SOTDMA) technology to meet this high broadcast rate and ensure reliable ship-to-ship operation.

Tuesday, March 18, 2008

Navigation Rules

Require vessels to display lights and shapes under certain conditions.

Navigation Lights

Recreational vessels are required to display navigation lights between sunset and sunrise and other periods of reduced visibility (fog, rain, haze, etc.). The U.S. Coast Guard Navigation Rules, International-Inland, specifies lighting requirements for every description of water craft. The information below is for power-driven and sailing vessels less than 65.5 feet / 20 meters in length.

Power-driven Vessels

(Sail Vessel under machinery power is considered a power-driven vessel).

If your power-driven vessel is less than 65.5 feet / 20 meters in length, then it must display navigation lights.

If your power-driven vessel is less than 39.4 feet / 12 meters in length, then it may display navigation lights.

Illustration of power-drive sailboat less than 39.4 feet, displaying red navigation light on port side of prow, green navigation light on starboard side of prow, and white navigation light atop mast visible from all directions.

If your power-driven vessel is less than 23 feet / 7 meters in length and its maximum speed cannot exceed 7 knots, then it may display an all-round white light, and if practicable, sidelights instead of the lights prescribed above. (For International Rules only)

For power-driven vessels less than 39.4 feet / 12 meters in length, the masthead or all-round white light must be at least 1 meter above the sidelights.

Sidelights may be a combination light, instead of two separate lights.

Sailing Vessels

If your sailing vessel is less than 65.6 feet / 20 meters in length, then it must display navigation lights as shown below

If your vessel is less than 23 feet / 7 meters in length, then it should display lights for a sailboat, such as above. As an option, your vessel may carry an electric torch (flashlight) or lightened lantern that can show a white light in sufficient time to prevent collision.

Vessel Under Oars

Your vessel may carry a flashlight or lighted lantern that can show a white light in sufficient time to prevent collision.

Lights and Shapes

To alert other vessels of conditions, which may be hazardous, there are requirements to display lights at night and shapes during the day.

Anchored Vessels

AT NIGHT: All vessels at anchor must display anchor lights. If your vessel is less than 164 feet / 50 meters in length, then its anchor light is an all-round white light visible where it can best be seen from all directions.

DURING THE DAY: All vessels at anchor must display, forward where it can be best seen, a black ball.

EXCEPTIONS: If your vessel is less than 23 feet / 7 meters in length, then it is not required to display an anchor light or shape unless it is anchored in or near a narrow channel, fairway or anchorage, or where other vessels normally navigate.

If your vessel is less than 65.6 feet / 20 meters in length, then it is not required to display an anchor light if it is anchored in Inland Waters in a special anchorage designated by the Secretary of Transportation.

Sailing Vessels Under Power (Machinery)

During the day, vessels under sail also being propelled by machinery, must exhibit forward, where best seen, a black conical shape with the apex pointing down.

EXCEPTION: If your vessel is less than 39.4 feet / 12 meters in length, then it is not required to display the shape in Inland Waters.

REMINDER: If you are operating your sail vessel at night using machinery or sail and machinery, then your vessel must display lights required for a power-driven vessel.

Restricted Maneuverability

The Navigation Rules require vessels restricted in their ability to maneuver to display appropriate day shapes or lights. To meet this requirement, if your vessel is engaged in diving activities during the day, then it must exhibit a rigid replica of the international code flag "Alpha" not less than 3.3 feet / 1 meter in height. If the diving activities are at night, then your vessel must display the navigation lights shown below. This requirement does not affect the use of a red and white divers flag, which may be required by State or local law to mark a diver's location. The "A" flag is a navigation signal indicating your vessel's restricted maneuverability and does not pertain to the diver.


Each Trip:
Make sure all exhaust clamps are in place and secure.
Look for exhaust leaking from the exhaust system components evidenced by rust and /or black streaking, water leaks, or corroded or cracked fittings.
Inspect rubber exhaust hoses for burned or cracked sections. All rubber hoses should be pliable and free of kinks.
Confirm that cooling water flows from the exhaust outlet when the engines and generator are started.
Listen for any change in exhaust sound that could indicate a failure of an exhaust component.
Test the operation of each carbon monoxide detector by pressing the test button.
Do not operate the vessel if any of these problems exist!
At Least Annually:
(Performed by a qualified marine technician)
Replace exhaust hoses if any evidence of cracking, charring or deterioration is found.
Inspect each water pump impeller and inspect the condition of the water pump housing. Replace if worn or cracked (refer to the engine and generator manuals for further information).
Inspect each of the metallic exhaust components for cracking, rusting, leaking or looseness. Pay particular attention to the cylinder head, exhaust manifold, and water injection elbow.
Clean, inspect and confirm the proper operation of the generator cooling water anti-siphon valve (if equipped).

Float Plan

"Click Here To View"

Fueling Precautions

Most fires and explosions happen during or after fueling. To prevent an accident follow these rules:
Portable tanks should be refueled ashore.
Close all hatches and other openings before fueling.
Extinguish all smoking materials.
Turn off engines, all electrical equipment, radios, stoves and other appliances.
Remove all passengers.
Keep the fill nozzle in contact with the tank and wipe up any spilled fuel.
Open all ports, hatches and doors to ventilate.
Run the blower for at least four minutes.
Check the bilges for fuel vapors before starting the engine.
Do the "sniff test". Sniff around to make sure there is no odor of gasoline anywhere in the boat.
Do not start the engine until all traces of fuel vapors are eliminated!!
Fuel Management
Practice the "One-Third Rule" by using:
One-third of the fuel going out
One-third to get back
One-third in reserve

Monday, March 17, 2008

Small Boat Anchoring

Here are some basic things to keep in mind when anchoring small boats:
Make sure you have the proper type of anchor such as a danforth, etc.
A three to six foot length of galvanized chain should be attached to the anchor. The chain will stand up to the abrasion of sand, rock or mud on the bottom much better than a fiber line.
A suitable length of nylon anchor line should be attached to the end of the chain (this combination is called the "Rode"). The nylon will stretch under heavy strain cushioning the impact of the waves or wind on the boat and the anchor.
Select an area that offers maximum shelter from wind, current and boat traffic.
Determine depth of water and type of bottom (preferably sand or mud).
Calculate amount of anchor line you will need. General rule: 5 to 7 times as much anchor line as the depth of water plus the distance from the water to where the anchor will attach to the bow. For example, if the water depth is 8 feet and it is 2 feet from the top of the water to your bow cleat, you would multiply 10 feet by 5 to 7 to get the amount of anchor line to put out.
Secure the anchor line to the bow cleat at the point you want it to stop.
Bring the bow of the vessel into the wind or current.
When you get to the spot you want to anchor, place the engine in neutral.
When the boat comes to a stop, slowly lower the anchor. Do not throw the anchor over, as it will tend to foul the anchor.
When all anchor line has been let out, back down on the anchor with engine in idle reverse to help set the anchor.
When anchor is firmly set, use landmarks in relation to the boat to make sure you are not drifting. Check these points often.
Do not anchor by the Stern
Anchoring a small boat by the stern has caused them to capsize and sink. The transom is usually squared off and has less freeboard than the bow. In a current, the force of the water can pull the stern under. The boat is also vulnerable to swamping by wave action. The weight of a motor, fuel tank, or other gear in the stern increases the risk.


Number of POB's=Length of Boat x Boat Width ÷ 15
Never overload your boat with passengers and cargo beyond its safe carrying capacity. Too many people and/or gear will cause the boat to become unstable. Always load your vessel so that it maintains proper trim. Here are some basic things to remember when loading your boat:
Distribute the load evenly fore and aft and from side to side.
Keep the load low.
Keep passengers seated.
Secure all loose gear to prevent shifting.
Do not exceed the "U.S. Coast Guard Maximum Capacities" information labe called the (Capacity Plate).
If there is no capacity plate, you can use the graph above as a guide to determine the maximum number of persons you can safely carry in calm weather. (The chart is for mono-hull boats less than 20ft in length.) A mono-hull is a boat, which makes a single "footprint" in the water when loaded to its rated capacity. A catamaran, trimaran, or a pontoon boat is not a mono-hull boat.

Sunday, March 16, 2008

Pre - Departure Check list

Before departure, always be sure your vessel is in good working condition and properly equipped for emergencies. Here is a list you can use, or modify to suit your own vessel's needs.

Minimum Federal Required Equipment
State Registration Documentation
State Numbering Displayed
Certificate of Documentation
Lifejackets (PFDs) - one for each person
Throwable PFD
Visual Distress Signals
Fire Extinguishers (fully charged)
Proper Ventilation
Backfire Flame Arrestor
Sound Producing Device(s)
Navigation lights
Oil Pollution Placard
Garbage Placard
Marine Sanitation Device
Navigation rules
Any Additional State Requirements

Besides meeting the federal requirements, you should carry additional safety equipment. The following additional items are suggested depending on the size, location and use of your boat:
Recommended Equipment

VHF Marine Radio
Anchor and Tackle
Chart(s) of Area & Navigation Tools
Magnetic Compass
Fenders and Boat Hook
Mooring Lines and Heaving line
Manual Bilge Pump or Bailing Device
Tool Kit
Spare Parts (fuses, spark plugs, belts, etc)
Spare Battery (fully charged)
Spare Propeller
Extra Fuel & Oil
Alternate Propulsion (paddles/oar)
Flashlight & Batteries
Search Light
First Aid Kit
Food and Water
Extra Clothing
AM - FM Radio
Cellular Phone

Safety Checks and Tests

Test Marine Radio (voice call)
Test Navigation and Anchor Lights
Test Steering (free movement)
Test Tilt / Trim
Test Bilge Pump
Check for any excessive water in bilges
Check Fuel System for any leaks
Check Engine Fluids
Ensure Boat Plug is properly installed / Have spare through Hull Plugs
Check Electrical System
Check Galley / Heating Systems
Check Gauges ( batteries)
Check Fuel Amount
Ensure Anchor is ready for use
Check load of vessel and secure gear from shifting
Make sure passengers know Emergency Procedures and Equipment Location
Everyone put on a Lifejacket to check for proper fitting.
Check the Weather Forecast

Backfire Flame Arrestor (BFA)

Gasoline engines installed in a vessel after April 25, 1940, except outboard motors, must be equipped with an acceptable means of backfire flame control. The device must be suitably attached to the air intake with a flame tight connection and is required to be Coast Guard approved or comply with SAE J-1928 or UL 1111 standards and marked accordingly.
It should be attached to the carburetor or carburetors a backfire flame arrestor that is approved for marine use and suitably secured to the air intake with flame tight connections, or any attachment to the carburetor or the engine air induction system by means of which flames caused by engine backfire will be dispersed to the atmosphere outside the watercraft in such a manner that the flames will not endanger the watercraft, persons on board or nearby watercraft and structures. All attachments shall be of a metallic construction with flame tight connections and firmly secured to withstand vibration, shock and engine backfire.

Saturday, March 15, 2008

Space Shuttle Endeavour

A friends Granddaughter who works for NASA sent me these pictures of the space shuttle Endeavour's past mission, I think the first picture is Hurricane Dean. Thought I would share these incredible pictures.

Friday, March 14, 2008

Radio Regulations

Most recreational vessels under 65.6ft/20m in length do not have to carry a marine radio. Any vessel that carries a marine radio must follow the rules of the Federal Communications Commission (FCC).

Radio Licenses
The FCC does not require operators of recreational vessels to carry a radio or to have an individual license to operate VHF marine radios (with or without digital selective calling capability), EPIRBs, or any type of radar. If you use a VHF marine radio equipped with digital selective calling will need to get a maritime mobile service identity (MMSI) number from the FCC. You cannot use digital selective calling without obtaining this (MMSI) number.

Vessels required to be licensed:
Vessels that use MF/HF single side-band radio, satellite communications, or telegraphy,
Power Driven vessels over 65.6 feet/20 meters in length.
Vessels used for commercial purposes including:
Vessels documented for commercial use, including commercial fishing vessels.
CG inspected vessels carrying more than 6 passengers.
Towboats more than 25.7 feet/7.8 meters in length.
Vessels of more than 100 tons certified to carry at least 1 passenger.
Cargo ships over 300 tons.
Any vessel, including a recreational vessel, on an international voyage.

Radio Listening Watch
Vessels not required to carry a radio (recreational vessels less than 65.6 feet/20 meters in length), but which carry a radio, must maintain a watch on channel 16 (156.800 MHz) whenever the radio is operating and not being used to communicate.

Distress Call Procedures
Make sure radio is on
Select Channel 16
Press/Hold the transmit button
Also give:
Vessel Name and/or Description
Position and/or Location
Nature of Emergency
Number of People on Board
Release transmit button
Wait for 10 seconds – If no response Repeat "MAYDAY" Call.

VHF Marine Radio Channels
The list of channels below is a partial listing of channels recreational boaters should be familiar with:

CH.06 Intership Safety
Used for ship-to-ship safety messages and search messages and ships and aircraft of the Coast Guard.

CH.09 Boater Calling: FCC has established this channel as a supplementary calling channel for recreational boaters in order to relieve congestion on VHF Channel 16.

CH.13, 67 Navigation Safety (Also known as the Bridge-to-Bridge channel): Ships greater than 20 meters in length maintain a listening watch on this channel in US waters. This channel is available to all ships. Messages must be about ship navigation (passing or meeting other ships). You must keep your messages short. Your power output must not be more than one watt. This is also the main working channel at most locks and drawbridges. Channel 67 is for lower Mississippi River only.

CH.16 International Distress, Safety and Calling: Use this channel to get the attention of another station (calling) or in emergencies. Ships required to carry a radio maintain a listening watch on this channel. USCG and most coast stations also maintain a listening watch on this channel.

CH. 21A, 23A, 83A U.S. Coast Guard only

CH. 22A Coast Guard Liaison and Maritime Safety Information Broadcasts: Announcements of urgent marine information broadcasts and storm warnings on Channel 16.

CH. 24, 25, 26, 27, 28, 84, 85, 85, 87
Public Correspondence (Marine Operator): Use these channels to call the marine operator at a public station. By contacting a public coast station, you can make and receive calls from telephones on shore. Except for dis-tress calls, public stations usually charge for this service.

CH.70 Digital Selective Calling: Use this channel for distress and safety calling and for general purpose calling using only digital selective calling (DSC).


All boats which use gasoline for electrical generation, mechanical power or propulsion are required to be equipped with a ventilation system. A natural ventilation system is required for each compartment in a boat that:

1. Contains a permanently installed gasoline engine.
2. Has openings between it and a compartment that requires ventilation.
3. Contains a permanently installed fuel tank and an electrical component that is not ignition-protected.
4. Contains a fuel tank that vents into that compartment (including a portable tank).
5. Contains a non-metallic fuel tank.

A natural ventilation system consists of:
A supply opening (duct / cowl) from the atmosphere (located on the exterior surface of the boat) or from a ventilated compartment or from a compartment that is open to the atmosphere.
And an exhaust opening into another ventilated compartment or an exhaust duct to the atmosphere.

Each exhaust opening or exhaust duct must originate in the lower one-third of the compartment. Each supply opening or supply duct and each exhaust opening or duct in a compartment must be above the normal accumulation of bilge water.
A powered ventilation system is required for each compartment in a boat that has a permanently installed gasoline engine with a cranking motor for remote starting.

A powered ventilation system consists of one or more exhaust blowers. Each intake duct for an exhaust blower must be in the lower one-third of the compartment and above the normal accumulation of bilge water.
For boats built prior to 1980, there was no requirement for a powered ventilation system, however, some boats were equipped with a blower.
The Coast Guard Ventilation Standard, a manufacturer requirement, applies to all boats built on or after August 1, 1980. Some builders began manufacturing boats in compliance with the Ventilation Standard as early as August 1978. If your boat was built on or after August 1, 1978 it might have been equipped with either

1. a natural ventilation system.
2. both a natural ventilation system and a powered ventilation system. If your boat bears a label containing the words "This boat complies with U.S. Coast Guard safety standards," you can assume that the design of your boat's ventilation system meets applicable regulations.

Gasoline vapors can explode. Before starting engine, operate blower at least 4 minutes and check engine compartment bilge for gasoline vapors.

Sound Producing Devices

The navigation rules require you to make sound signals under certain situations. Meeting, crossing and overtaking situations described in the Navigation Rules section are examples of when sound signals are required. Recreational vessels are also required to sound signals during periods of reduced visibility.
When operating on Inland Waters of the United States, vessels 39.4 feet or 12 meters or more in length are required to carry on board a whistle or horn, and a bell.
Note: The requirement to carry a bell on board no longer applies to vessels operating on International Waters.
Any vessel less than 39.4 feet 12 meters in length may carry a whistle or horn, or some other means to make an efficient sound signal to signal your intentions and to signal your position in periods of reduced visibility.
Any vessel less than 39.4 feet 12 meters in length is required to make an efficient sound signal to signal your intentions and to signal your position in periods of reduced visibility.

Thursday, March 13, 2008

Fire Extinguishers

Fire Extinguishers are classified by a letter and number symbol. The letter indicates the type fire the unit is designed to extinguish (Type B for example are designed to extinguish flammable liquids such as gasoline, oil and grease fires). The number indicates the relative size of the extinguisher. The higher the number, the larger the extinguisher.
Coast Guard approved extinguishers required for boats are hand portable, either B-I or B-II classification and have a specific marine type mounting bracket. Fire extinguishers should be mounted in a accessible position, away from the areas where a fire could start such as the galley or the engine compartment. Look for the part of the label that says "Marine Type USCG"
Make sure Type B is indicated.
Portable extinguishers will be either size I or II. Size III and larger are too big for use on most recreational boats. Fire Extinguishers are required on boats when any of the following conditions exist:
1. Inboard engines are installed.
2. There are closed compartments and compartments under seats where portable fuel tanks may be stored.
3. There are double bottoms not sealed to the hull or which are not completely filled with flotation materials.
4. There are closed living spaces.
5. There are closed stowage compartments in which combustible or flammable materials are stored.
6. There are permanently installed fuel tanks. (Fuel tanks secured so they cannot be moved in case of fire or other emergency are considered permanently installed. There are no gallon capacity limits to determine if a fuel tank is portable. If the weight of a fuel tank is such that persons on board cannot move it, the Coast Guard considers it permanently installed.)

Fire Extinguisher Maintenance
Inspect extinguishers monthly to make sure that:
Seals and tamper indicators are not broken or missing.
Pressure gauges or indicators read in the operable range. (Note: CO2 extinguishers do not have gauges.)
There is no obvious physical damage, rust, corrosion, leakage or clogged nozzles.
Weigh extinguishers annually to assure that the minimum weight is as stated on the extinguisher label.
Fire extinguishers that do not satisfy the above requirements or that have been partially emptied must be replaced or taken to a qualified fire extinguisher servicing company for recharge.

Required Number of Fire Extinguishers
The number of fire extinguishers required on a recreational boat are based on the overall length of the boat. In the case where a Coast Guard approved fire extinguishing system is installed for the protection of the engine compartment, the required number of units may be reduced in accordance with the chart.

Determine Position By Soundings

A position obtained by sounding is usually approximate. Accuracy of this type of position depends on the following:

How completely and accurately depths are indicated on the chart.
The irregularity of the depths.

It is impossible to obtain a position by soundings if the ship is located in an area where depth is uniform. Position by soundings serves as a check on a fix taken by some other means.

Let's say you have only one spot on or near your DR track where water depth is 6 fathoms and the depth over the rest of the area for miles around is 20 fathoms. If you record 6 fathoms, you can be certain you are located at the one point where a 6-fathom depth was shown on the chart.

Piloting by soundings is not that simple. What you really do is get a contour of the bottom you are passing over and try to match it up with a similar contour shown by the depth figures on the chart. Here is a method you can use:

Draw a straight line on a piece of transparent paper or plastic. Calculate how far apart your soundings will be, in other words, the length of the ship’s run between soundings and mark off distances on the line to the scale of the chart. Alongside each mark representing a sounding, record the depth obtained at that sounding. The line represents the ship’s course. The line of soundings recorded on the overlay should fit the depth marks on the chart somewhere near your DR track. If it makes an accurate fit, it probably is a close approximation of the course the ship is actually making good.

Danger Bearings

It is possible to keep a ship in safe water without frequent fixes through the use of danger bearings. The figure above shows a shoal that presents a hazard to navigation, a prominent landmark at point A, and a ship proceeding along the coastline on course BC. To construct a danger bearing, line AX is drawn from point A tangent to the outer edge of the danger. If the bearing of point A remains greater than the danger bearing, the ship is in safe water, as with YA and ZA. The reverse is true when the danger is to port, the danger angle must remain greater than the angle to point A.
Wind or current could set the ship toward the shoal. However, even before a fix could be taken, this situation would be indicated by repeated bearings of point A.

Wednesday, March 12, 2008

Visual Distress Signals

All vessels used on coastal waters, the Great Lakes, territorial seas, and those waters connected to them, up to a point where a body of water is less than two miles wide, must be equipped with U.S.C.G. Approved visual distress signals. Vessels owned in the United States operating on the high seas must have U.S.C.G. Approved visual distress signals.
These vessels are not required to carry day signals but must carry night signals when operating from sunset to sunrise:
1. Recreational boats less than 16 feet in length
2. Boats participating in organized events such as races, regattas, or marine parades.
3. Open sailboats less than 26 feet in length not equipped with propulsion machinery.
4. Manually propelled boats.
Pyrotechnic Devices
Pyrotechnic Visual Distress Signals must be Coast Guard Approved, in serviceable condition, and readily accessible.
They are marked with an expiration date. Expired signals may be carried as extra equipment, but can not be counted toward meeting the visual distress signal requirement, since they are unreliable.
If pyrotechnic devices are selected a minimum of three are required. Which is, three signals for day use and three signals for night. There are some pyrotechnic signals that meet both day and night use requirements.
Pyrotechnic devices should be stored in a cool, dry location.
A watertight container painted red or orange and marked "DISTRESS SIGNALS" or "FLARES" is recommended.
U.S.C.G. Approved Pyrotechnic Visual Distress Signals and associated devices include:
Pyrotechnic red flares, hand-held or aerial.
Pyrotechnic orange smoke, hand-held or floating.
Launchers for aerial red meteors or parachute flares.
Non-Pyrotechnic Devices
Non-Pyrotechnic Visual Distress Signals must be in serviceable condition, readily accessible, and certified by the manufacturer as complying with U.S.C.G. requirements. They include:
Orange distress flag
Day signal only.
Must be at least 3 x 3 feet with a black square and ball on an orange background.
Must be marked with an indication that it meets Coast Guard requirements in 46 CFR 160.072.
Most distinctive when attached and waved on a paddle, boathook, or flown from a mast.
Electric distress light
Accepted for night use only
Automatically flashes the international SOS distress signal: (... — — — ...)
Must be marked with an indication that it meets Coast Guard requirements in 46 CFR 161.013.
Under Inland Navigation Rules, a high intensity white light flashing at regular intervals from 50-70 times per minute is considered a distress signal. Such devices do NOT count toward meeting the visual distress signal requirement, however.
Regulations prohibit display of visual distress signals on the water under any circumstances except when assistance is required to prevent immediate or potential danger to persons on board a vessel.
All distress signals have distinct advantages and disadvantages. No single device is ideal under all conditions or suitable for all purposes. Pyrotechnics are universally recognized as distress signals. Pistol launched and hand-held parachute flares and meteors have many characteristics of a firearm and must be handled with caution. In some states they are considered a firearm and prohibited from use.
The following are just a few of the variety and combination of devices which can be carried in order to meet the requirements:
Three hand-held red flares (day and night).
One hand-held red flare and two parachute flares (day and night).
One hand-held orange smoke signal, two floating orange smoke signals (day) and one electric distress light (night only).

Tuesday, March 11, 2008

Distance Of A Object By Two Bearings

A quick easy solution can be provided by using the extract of TABLE 7 from Pub. No. 9, American Practical Navigator (Vol. II) "Green Bowditch". To determine the distance of an object as a vessel steams past, observe two bearings of the object, note the time interval between the bearings, and determine the distance run. Determine the angular difference between the course and the first bearing and the angular difference between the course and the second bearing. Using the extract of TABLE 7, find the difference in degrees between the course and the first bearing going across the top of the table to that degree. Then go down that column until you come to the degrees of difference between the course and the second bearing. Multiply the distance run between bearings by the number in the first column to find the distance of the object at the time of the second bearing and then by the number in the second column to find the distance when you come abeam.

Note: The solution from TABLE 7, as with any of the "special cases," is accurate only if a steady course has been steered, the vessel has been unaffected by the current, and the speed used is the speed over the ground.

Example Problem : The course is 050°, the speed is 15 knots, the first bearing of the lighthouse at 1130 was 024° , and the second bearing of the lighthouse at 1140 was 359° .

Required: The distance the ship was off at 1140 at the second bearing and the distance off when abeam.

Solution: The distance run between the first and second bearing:

D = 15 x 10 ÷ 60 = 150 ÷ 60 = 2.5 miles

Use Table above: Bowditch Table 7 (Green)

The difference between the course and the first bearing is 26° (050° – 024° ). The difference between the course and the second bearing is 51° (050° + 360° – 359° ). From TABLE 7 the two numbers (factors) are 1.04 and 0.81. This is found by interpolation between 50° and 52° for the second bearing.

Distance from lighthouse at second bearing:

1.04 X 2.5 = 2.6 miles.

Distance off lighthouse when abeam:

0.81 X 2.5 = 2.0 miles.

Two Bearings Of A Single Object


A running fix can be obtained by using the mathematical relationships involved as shown above. A ship is steaming past lighthouse D. At point A, a bearing of D is observed and expressed as degrees right or left of the course (a relative bearing if the ship is on course). At a later time at point B, a second bearing is taken of D and expressed the same as before. At point C, the lighthouse is broad on the beam. The angles at A, B, and C are known, as are the distances between these points. Trigonometry can be used to find the distance from D at any bearing. Distance and bearing provide fix.

Factors Affecting DR Positions

A DR track is based on an assumption of making good an exact course and speed. There are many factors prevailing against the ship to prevent this. Some of these factors are poor steering and the inability to make good the plotted speed, current, and leeway.

Terms that must be understood in regards to dead reckoning include:

This is the horizontal motion of water. The direction in which the water is moving is called the set and the velocity of the flow is called the drift.

This is the intended horizontal direction of travel with respect to the earth, taking into consideration known or predicted offsetting effects such as current, wind, and seas.
Speed of Advance
This is the intended speed with respect to the earth, taking into consideration the effect of known or predicted current. SOA is also used to designate the average speed that must be made good to arrive at a destination at a specified time.

This is the direction toward which the current is flowing. If the broader definition of "current" is used, the resultant direction is of all offsetting influences. Note that the description of the set of a current is directly opposite from the naming of a wind, a westerly current sets toward the west, a westerly wind blows from the west.

This is the speed of a current (or the speed of the resultant of all offsetting influences), usually stated in knots. However, some publications, notably pilot charts and atlases, express drift as nautical miles per day.

Course Made Good
CMG is the resultant direction from a given point of departure to a subsequent position. It is the direction of the net movement from one point to another, disregarding any intermediate course changes en route. This will differ from the track if the correct allowance for current was not made.

Speed Made Good
SMG is the net speed based on distance and time of passage directly from one point to another, disregarding any intermediate speed change. SMG is speed along the CMG.

Course Over The Ground
COG is the actual path of the vessel with respect to the earth. This may differ from CMG if there are intermediate course changes, steering inaccuracies, varying offsetting influences, and so forth. In current sailing triangles, CMG (not COG) is used.

Speed Over The Ground
SOG is the ship’s actual speed with respect to the earth along the COG. In current sailing, SMG (not SOG) is used.