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Advice from a Boat Physician: Don’t Neglect Your Sea Valve

As I grow older the necessity of exercise becomes more evident to maintain good health. In order to maintain flexibility and strength, one has to work those muscles and joints, as they say, no pain no gain.

One of the most neglected components on our vessels is the lowly sea valve. Nestled below the cabin sole in the usually deep dark reaches of our bilges live these necessary and vital portals to the deep. Through these values flow the lifeblood of our vessels. Water that cools our engines, supplies our heating and air conditioning systems, drains our decks and cockpits, and disposes of wastewater.

Now, I consider myself a boat physician of sorts. I diagnose problems and either write prescriptions or outline a course of physical therapy. Many of my valve patients are suffering from either lockjaw or severe arthritis. They either won’t open or close at all or are so stiff from lack of exercise that you fear you are going to break them during the physical exam.

What these simple mechanical marvels need is a disciplined regime of exercise.

“One two – one two – up down, turn around, work it out; you can do it!” Does that sound like Denise Austin?



Seacock – A type of valve used to control intake or discharge of water through the hull. It is operated by a lever-type handle, usually operating through a 90-degree arc, giving a clear indication of whether it is open or shut.


All piping, tubing, or hose lines penetrating the hull below the maximum heeled waterline, under all normal conditions of trim and heel, shall be equipped with a seacock to stoop the admission of water in the event of failure of pipes, tubing, or hose.


A seacock shall be securely mounted so that the system will withstand a 500-pound static force applied for 30 seconds to the inboard end of its connecting fitting at any point in its most vulnerable direction without the system failing to perform as intended. Seacocks shall be readily accessible as installed and so oriented that their handles are easy to operate. If a flanged seacock is used, its flange shall be securely mounted to the hull.

Whether you have straight, tapered, or ball valves, they all need a workout. If you have

gate valves, you need to consider replacement, as these valves have no place in the marine environment. Straight or tapered valves should be disassembled at least every other haul, inspected, cleaned, and lubricated. Modern Teflon seated ball valves are sort of self-cleaning when operated. Composite plastic ball valves are not high on my list due to the fact that they are just not as strong as their bronze counterparts and can break when the frictional resistance from age or fouling becomes too great.

When you are doing your exercise program, be sure to inspect the clamps and delivery hoses for signs of deterioration. Rubber hoses don’t last much longer than seven or eight years. Look for age cracks and signs of chafe. Pay special attention to connections where the hose may have been stretched or forced over a fitting. Look at your hose clamps. If the worm drive is rusty, it probably was a low-grade stainless steel. Perforated clamps usually break across the perforations; if it looks bad, it probably is. Now is the time for replacement. I can’t tell you how many times I’ve had these things break off in my hand when I touched it. You would not believe how many boat owners don’t know where supply valves are located.

Reacquaint yourself with the vessel’s circulatory system so you’ll know where to apply the pressure to stem the flow if you ever find yourself offshore with arterial bleeding. How about hanging a proper-sized (DC) damage control bung from each valve just in case of a failure? Consider a high-water bilge alarm as an excellent equipment betterment.

Believe me, no addition can save you more grief than an early warning device. Keep that water flowing through and not into your vessel with a good program of exercise and inspection, and remember that the Lord loves sailors.

© Capt. Neil K. Haynes (Originally published in 1999)


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