Nautical Know How - Safe Boating Tips

		Nautical Safety Tips
	Float Plan: You can print and use for your next voyage.	For years, airline pilots have been required to file a flight plan with the FAA prior to setting off on a trip. Although the U.S. Coast Guard does not require one, it's a good idea to prepare a float plan and give it to a responsible person before getting underway. If this person has not heard from you by the date and time you have specified on your float plan, he or she should follow your specific instructions regarding notification of your status to the local U.S.C.G. station.

	Pre-Departure Checklist:	After you've completed your Float Plan but before you leave the dock, check out the items on this list.

	Tip Bilge Pumps	It is important to frequently test your bilge pumps by switching from the automatic to manual position on the bilge pump switch. However, this doesn't guarantee that the pump will work when unattended. You should also check the automatic float switch by manually raising it to make sure that it turns on the pump. Also, check for debris or corrosion that might keep it from floating up properly. If this switch fails the pump won't turn on and your boat could take on sufficient water over time to do serious damage.
	Tip Through-hull Fittings	Every through-hull fitting in your boat is a potential hole that could sink you in a matter of minutes. Although they are out of sight and, at times, difficult to get at, through-hulls need careful routine checking, at minimum every three months. Many through-hulls such as engine-cooling intakes and sink or cockpit drains, tend to be left open continuously and the valves may stick in the open position. You should operate the valve by turning it on and off to make sure that when an attached hose fails you can stop the water flow. As an additional precaution you should get wooden bungs (tapered soft wooden plugs) for each through-hull in your boat. (You can get them at most Marine Supply stores.) Make sure that they are the proper diameter to fit in the through-hull. Once you get them back to your boat, don’t just throw them in a drawer. Take each appropriate size to the through-hull it fits, drill a hole in the larger end and thread a string or monofilament line through and tie it to the through-hull fitting. When the inevitable happens you won’t have to go looking for the bung. Just reach down, put the tapered end in the hole, and press down until tight and the leak has stopped. Remember, a two inch hole just a few feet below the waterline can sink a 30’ boat in just a few minutes.
	Distance to the Horizon	Have you ever been out on a leisurely cruise and suddenly wondered, "How far it is to the horizon?" Or maybe your destination is a port that has a lighthouse and you wonder "How far away will I be when I see the lighthouse?" (Well, you're in luck, even if you are a sick unit that thinks of these sorts of things - so are we.) We have the answer! Of course you can find tables that do the calculation for you in numerous navigation books, almost every book which talks about passagemaking, the Coast Pilot, almanacs, etc. But what if you didn't have any of these references onboard? How could you calculate the distance to the horizon or the "distance off" if you know the height of an object? It's simple, really. If you want to know the distance to the horizon you simply have to know your height of eye. That is the distance that your eyes are off the surface of the water. If you're in a jon boat, that would probably be about three feet (if you are sitting like you should be in a jon boat). Of course if you were in a jon boat you probably wouldn't care how far the horizon was. Anyway, I digress. If you are on the tuna tower of a sport fishing boat you may be 15, 20, 25 feet above the surface of the water. Once you know your height of eye you simply plug that into the following formula: 1.17 times the square root of your height of eye = Distance to the horizon in nautical miles For example, if your height of eye was 9 feet above the surface of the water, the formula would be: 1.17 times the square root of 9 = Distance to the horizon in nautical miles. *1.17 3 = 3.51 nautical miles If you want to calculate the distance at which an object becomes visible, you must know your height of eye and the height of the object. You then do the same calculation for your distance to the horizon and the object's distance to the horizon and add the distances together. For example: You have the same height of eye of 9 feet so your distance to the horizon is still 3.51 nautical miles. You're approaching a port that has a lighthouse that is shown on your chart to have a height of 81 feet. Using the same formula you would find that 1.17 times the square root of 81 (1.17 * 9) = 10.53 nautical miles (the light house can be seen 10.53 nautical miles over the horizon)** By adding the two together: 3.51 + 10.53 = 14.04 nautical miles, you should be able to see the lighthouse when you are 14.04 nautical miles away.

	*Lightning*	Cone of Protection from Lightning Even though the odds are in your favor that your boat may never be hit by lightning, if it happens it can have devastating effects. Don't take a chance, protect yourself. If you are in a small boat and close to shore when a thunderstorm approaches, get in and off the water immediately. Better yet, don't go out if thunderstorms are predicted. But what if you are miles offshore and a storm pops up? Hopefully, you have prepared in advance. The voltages involved in lightning are so high that even materials that would normally be considered non-conductive become conductors, including the human body. The voltages are so massive that if they start to travel through a boat's structure - say through its mast - then meet with high resistance (for instance, the hull skin) the current discharge, in its attempt to reach ground, may simply blow a hole in the non-conductive barrier. The safety conscious Captain should make sure that his vessel is properly protected. Reference should be made in detail to the standards for lightning protection as set forth by the American Boat and Yacht Council (ABYC) and the job should be performed by a licensed marine electrician. In theory, a lightning protection system is used to create what is know as a "Faraday's cage," so called after the late nineteenth-century scientist Michael Faraday. The principle of a Faraday's cage is to provide a surrounding, well-grounded, metal structure, all of whose parts are bonded together and carry the same electrical potential. Such a "cage" attracts and carries any lightning strike to ground much like lightning rods on buildings. In other words, you need to provide an unobstructed way for the lightning to dissipate its energy to ground (the water surrounding you). Faraday himself risked his own life to prove this theory. The additional benefit of a lightning protection system is that it tends to bleed off any charge build-up in the general vicinity, possibly averting a lightning strike in the first place. So how does a lightning protection system work? In a boat, the "cage" is formed by bonding together, with heavy conductors, the vessel's mast and all other major metal masses. A marine electrician must tie in the engines, stoves, air conditioning compressors, railings, arches etc. with a low resistance wire which would ultimately provide a conductive path to ground (the water) usually via the engine and propeller shaft, keel bolts, or better yet, a separate external ground plate at least 1 square foot in dimension. It is important that you ensure that your crew fall within the protection of the "cage," something not always feasible when the vessel is not built of steel or aluminum. On fiberglass or wooden boats it is advantageous to have a mast or other conductive metal protrusion extending well above the vessel, creating what is known as a "cone" or zone of protection. It is generally accepted that this cone of protection extends 45 degrees, all around, from the tip of the metal protrusion. This means that if the aluminum mast of the average sailing vessel is properly bonded to the vessel's other major metal masses and is given a direct, low-resistance conductive path to ground, the entire boat should fall within the protected zone. If the vessel has a wooden or composite mast, a marine electrician can achieve the same effect by installing a 6 to 12 inch metal spike at the top and running a heavy conductor down the mast and as directly as possible to ground, usually through the engine and propeller shaft. Again, refer to the ABYC standards and have a professional marine electrician install your lightning protection. This is not a do-it-yourself project.