Nothing is more vital to the integrity of your boat than its seacocks. Have a problem with one of them, and you literally could be sunk. Depending on the size and type of your boat, you could have a few, or quite a few, down in your bilge, but you’ll certainly have them for your engine(s), genset, head(s) and other equipment. It’s also a good idea to have a mallet and tapered plugs, sized to fit, ready to go in case one of them totally fails.
Here’s a good story from Sea about how to care for seacocks and how to prevent future problems. It’s easy to forget about them; generally, out of sight means out of mind. But make a schedule to check your seacocks on a regular basis; like any other piece of machinery, they can work perfectly until they don’t.
A visual inspection is fine, but then you need to make sure you can open and close each seacock easily, and that the handle moves through its full range without being blocked by something else. Then you can start inspecting the hose and clamps and think about swabbing the ball with waterproof grease. Read more: