Replacing a seacock while in the water?

[SVTwilight]

If the water is warm enough, take a handful of plumbers putty or a toilet wax ring (you already have this on board for emergency leaks right?) , and snorkel down on the outside and put it firmly in place at the thru hull, pushing it into the opening a little. Then on the inside, remove the seacock. No water will ingress.

When done take a butter knife back in the water with you and remove the plumbers putty, making certain to carve out any of the putty that got up into the thru hull.

Have a wood plug handy on the inside work just to calm your nerves.

Duck soup...

[KP44]

Originally Posted by tce001

What is the brand of the seacock that failed? I'm just in the process of replacing mine and was thinking of going composite.

I have been replacing all my seacocks, and throughhulls, with marleron. The first one replaced was the engine raw water; done at least 10 years ago.
I just did 2 more a month ago. The new seacocks never bind, always close and open smoothly and evenly. Very dependable and no bonding issues. No galvanic action. I had 13 holes (seacocks) in my boat when I bought it and will replace the remaining 5 bronze throughhulls next summer during haul-out.