But I operate them every time I go onboard or leave the boat on the mooring, out of habit. Except for the two cockpit scuppers, I leave open of course. But I operate them every spring as well as all others and grease them if they're sticking at all. I give them and hoses a good look and firm yank each spring.

I'm careful not to have anything large nearby that can shift and hit one. I wouldn't expect them to hold up to that.

When I disassemble them to grease(which is very simple), I check the body, which is a chunk of bronze with a hole in it, and check the,...other part, which is a chunk of brozne with a hole in it, and I can't see any wear. The thru hulls I check from the outside(and inspect from inside the hull) at haul out to see they're not thinning. That's about it. I wish all things in life were so simple.

I've had one bronze seacock fail. It was not used for many years and froze. The nut and bolt broke off when I backed up the nuts to protect the threads as I "tapped" it. No problem, I just held it together with something until it could be changed.

I drew a "key" CAD file of the boat to locate all seacocks, etc. This was done with my kids in mind using the boat. Now I keep a few "keys" onboard(here's one behind the plexi panel next to boat papers) in easy to see places. It might help in any emergency if I'm not onboard. I can't imagine trying to find hoses and seacocks on an unknown boat.