The 1st Commandment of Boating

Thou Shalt Not Sink

February 1, 2002

Although there are an infinite number of hints and tips for things you should do in the practice of good seamanship, there are only four absolute commandments. They are at the core and heart of boating, without which all else means nothing. The most important of these four is to stay afloat. What are the other three? We’ll tell you in upcoming columns.

A vessel may be defined as an object that keeps water either in or out; it is the latter sort that concerns us. Keeping the water out is not only the first and most important commandment of seamanship, it is also the only one that is necessary. All the others are mere niceties. Going on the water without drowning is sure proof of successful seamanship-drowning is equally sure proof that seamanship failed. Whatever else may befall your vessel, if you can keep water out of it, you won’t drown.

The first thing to do every time you board a vessel is to look in the bilge to see if it’s holding any water. Don’t assume a dry bilge. Look and see for yourself. Even the best intentions and care can’t ensure a dry bilge. Imagine your vessel half full of water. Then imagine how you’ll get it out. The quicker, the better, because more water may be coming in.


Pumps can remove water from vessels. Big diaphragm manual pumps and big lift pumps can move water fairly quickly. Small pumps move water slowly. Have big pumps, not small ones. There are pumps that run on gasoline and pumps that run on electricity, as well as those that run on elbow grease. If the gas or electrically powered models are big pumps, they’ll likely move water faster than a seaman-operated pump. But the seaman-operated pump will nearly always start and, within reason, run as long as needed. Portable pumps are more versatile and repairable than fixed pumps. Buckets even more so. If there’s enough water inside the vessel to endanger it, most of it will probably be accessible to bailing with a bucket.

If the water gains on bailing or pumping, the only way to keep from sinking may be to find a way to support the vessel other than by its own buoyancy. Try to borrow buoyancy from other vessels that may have a reserve of it. This is a rather tricky business, fraught with potential danger to rescuer and rescued. Many strong lines and fenders would be the chief ingredients for success.

Think of supporting your vessel with a shoal bottom under its keel. Compared to sinking, running it ashore is the lesser evil. If you think you can get to shore before you sink, then you may choose what part of the shore you’ll use for support. Look primarily for shelter from waves and secondarily for evenness and softness of bottom.


Even though your vessel has been designed and built specifically to keep water out, there are many ways for it to get in-some obvious, some insidious.

If a vessel is made from more than one piece, above or below the waterline, the joint or joints may leak. Leaks occur because the joint opens, possibly because its fastenings are being carried away or the stuff that was crammed into it to make it watertight is coming adrift. These calamities are generally caused by sudden stress on the hull, either by the hull’s hitting something, such as a wave, the bottom, or another hull, or by severe stress being imparted to the hull. Pay close attention to your hull-to-deck and other joints, and do everything in your power to make them strong and watertight before you put your vessel in the water.

Some builders drill holes right through the hulls of vessels. And the truth is that some boaters give a higher priority to pumping the water closets and draining their sinks than they do to keeping the water out of their vessels. Perhaps they think they can do both at once. If you yourself are tempted to try these tricks, remember that it’s dangerous business to drill holes in something that is supposed to keep water out.


If you drill a hole through the hull of your vessel and stick the pipe that drains the sink into it, make the pipe as strong as the hull, because you are now depending on the pipe as much as on the hull to keep the water out of your vessel. Put a valve in the pipe just as close to the hull as you can. You can use the valve to shut the sea out if the pipe should fail for any reason. Of course, the valve must be as strong as the hull. If you drill a hole through your hull, don’t make it inaccessible by covering it with built-in furniture. Be able to reach those holes. Cut a wooden plug to fit every hole you drill in your hull, and keep the plugs handy. Be prepared to stop leaks. Be ready to plug holes you have drilled in your hull. Be prepared to stop water from coming in through joints that have opened up. Be ready to cover large holes created by catastrophe.

Waves can make it difficult to keep water out of a vessel. Driven by wind, they can become large and steep, breaking right over the top of the vessel, and they may become even larger and steeper and catch the vessel in their crest as they break, flinging it right down on its beam ends or, worse, turning it upside down. It’s prudent for the seaman to study this phenomenon of wave and wind from the security of dry land. Study the Beaufort Scale carefully, using a complete copy that gives the time-honored descriptions of the numbered forces, words well used by seamen since time long before Beaufort, words such as fresh breeze and moderate gale. Note the verbal descriptions of the sea for each wind force; think about how your vessel would react to each wind force. A vessel will generally take more wind and sea than you think, which is A Very Good Thing.

Don’t try to outguess thunder squalls. Assume every one of them is going to blow a living gale. Although strong winds can lead indirectly to water entering your vessel, there is nothing like a big wave for undoing directly and suddenly all your efforts at keeping the water out. Observe waves on all scales from mud puddle ripples to great ocean breakers. Watch how small waves combine and how waves run in from new directions. When big seas do this, they are most dangerous.


The thing to be avoided is taking on large amounts of water by shipping a sea. Waves contain a great deal of water, and some or all of it coming on board may find its way inside. A great deal of water traveling along at some speed represents a great deal of force, and this force may damage your vessel. The same people who groan under the weight of a 10-gallon jerry can of water pretend to be surprised when big, fast-moving seas bend heavy stainless-steel stanchions.

You can avoid shipping a head sea by steering carefully and by slowing down your vessel. It’s amazing how much small differences in speed make in a head sea. To avoid shipping a sea over the stern of your vessel-getting pooped, they call it-you can steer carefully or round up and take them on the bow. As long as you keep a big breaking sea astern, however, there is always danger of getting pooped. The ultimate weapon for dealing with dangerous breakers at sea is the parachute sea anchor. Your best chance of keeping the water out of your vessel in survival conditions is to lie to such an anchor. With a little luck, always a factor in seamanship, its vortex will keep the seas from breaking onboard.

Though shipping a sea is certainly to be avoided, it need not be a disaster if your vessel is decked, has a watertight cockpit, and has its deck openings strongly sealed. It’s good for deck openings to be as near the centerline as possible. The more deck openings, the harder to keep the water out.

The worst thing the sea can do is turn your vessel upside down. A wave may roll it right down on its beam ends and on over. Or one may lift its stern so high that its bow digs in, the boat trips on it and does a somersault, with a half-twist thrown in or not, as the case may be. Pitchpoling is the all-too-descriptive term used.

Shipping a sea in an open boat, a half-decked boat, or a boat with an open cockpit is something else again. It is A Very Good Thing, of course, if such vessels can remain afloat even though full of water. As long as your vessel stays afloat, stay with it. Your greatest chance of saving lives is to save your vessel. When that proves impossible, and your vessel sinks, then it is A Very Good Thing to have a life raft or dinghy to climb into. That gives you another tiny vessel out of which to try to keep the water. If you don’t have such a vessel, you at least ought to have something that will float for a long time. Amen.

The book The Elements of Seamanship, from which this article has been condensed, is available from The Gestalt Journal Press, Box 990, Highland, NY 12528-0990, [email protected]


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