The long forgotten seacock….yeah the valve in the bottom of the bilge that separates the world’s oceans from the inside of your boat! If this valve has such a BIG job, why is it that most of us never pay any attention to it?

At least four times a year minimum (and best to actuate them monthly) all of your seacocks or ball valves (depending on what was installed in your boat) needs to be “worked” to ensure that the valve is in working order. Additionally, a spray silicon lubricant should be sprayed on the moving parts to help keep working smoothly. If at all possible it would be ideal to check all of these valves when the boat is out of the water. If there is a problem with one of them, then it is more convenient to repair or replace. However, don’t delay opening and closing each ball valve or seacock to ensure proper functionality just because your boat is still in the water.  If you do have a problem with one of the valves, it obviously is better to find out when you are at the dock and not 50 miles offshore!

There are several types of these valves, each requiring slightly different care.

First there are gate valves. Let’s hope you don’t have any of these as they are the most prone to fail and have been prohibited to be used byNational Marine Manufacturers Association approved boat manufacturers by American Boat and Yacht Counsel  It is advisable to replace any of this type of valve at the earliest possible opportunity. It is best to have skilled marine technician that is familiar with ABYC Standards replace the valves.

Ball Valves- Pretty simple for routine maintenance. First make sure that the component that the valve supplying water to is turned off. Now, simply close and open the valve several times to ensure smooth and easy operation. If the valve is stuck either in the open or closed position, you may want to employ a certified marine mechanic to see if he/she can “free” it up. If not, then it needs to be replaced. In the event that a hose or seal fails “down stream” of this valve and it can NOT be closed, it gets to be pretty exciting on board as you have to “MacGyver” a field fix out on the water before your boat sinks!  Also,  while opening and closing the valve, look closely at the bronze housing for signs of corrosion and/or electrolysis. If it has any pitting or is pinkish in color, have it replaced!

Seacocks- Again, pretty simple and is treated the same as a ball valve (see above). The only real difference between the two is that some seacocks can be disassembled for inspection and greasing of the interior housing and valve assembly. Newer seacocks are designed and constructed in similar fashion to ball valves and are actually a version of a ball valve. Older and some larger seacocks have a cone shaped rotating inner valve assembly that sits inside of the housing. It is held in place with a nut and washer on the opposite of the handle along the rotating axis. When the boat is hauled, the seacock should be disassembled to have the housing and valve assembly cleaned, inspected and lubricated with water proof grease before being reassembled.

When your boat is hauled this is the time to carefully inspect all seacocks. Remove the hose attached inside. Have someone inside the boatactuate the seacock while you are outside looking up into the seacock with a flashlight. Remove marine growth and any other obstructions and insure smooth operation. And finally, completely remove seacocks for disassembly and inspection every four years, which also ensures that you’ll be renewing the bedding compound when they’re reinstalled.


Richard Strauss is a broker with Galati Yacht Sales, and has been around boats nearly all his life. He has a degree in Marine Technology from Florida Tech, and has worked for well-known boat manufacturers as well as operated his own boat repair facility for fourteen years. When he is not busy helping customers find the boat of their dreams or sell their existing boat, he can be found cruising the waters of Sarasota Bay. You can contact Richard at or 239-633-5724.

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