thru-hulls and seacocks

[Kevin]

I must replace the thru hull fitting for the head sink drain on my 1979 Oday 23. Although the fitting exits the hull above the water line, I am wondering if I should have a seacock behind the thru hull fitting. None of the thru hull fittings currently have seacocks. I occasionally notice a little water in the sink (and on the floor)after sailing fast and heeled over on the port side. I suspect it is siphoning back in through the drain. Has anyone else experienced this and if so, how did you cure it? And what about those seacocks? Should I just make up some wooden plugs?

 

[gene]

thru hulls

I just bought a 25 and will install bronze ball valves on my thru hulls. I would get seacocks if I needed to replace thru hulls as you do. I like the Marlone?? no corrosion but expensive. my 2 pennies.gene

 

[Keith]

Conventional Wisdom

Conventional wisdom on thru-hulls is you should have a seacock on any thru hull below the waterline, especially if the plumbing is hoses. If you are a trailer-sailor, then having no seacocks should be OK. If you leave the boat unattended in the water, most boat publications I have read say to install seacocks and close them when you are gone.I have a 1973 Oday23. The factory thru-hull for my sink/icebox drain was plastic with no valve, and is actually just below waterline. I have replaced it with a bronze thru-hull, with a bronze ball valve. With the valve open, I never experienced back-flow enough to reach the sink, although our drain hose routings may be different. With metal fittings, they should be inspected every spring to assure you don't have corrosion issues. Having a properly sized plug on board for each thru-hull item (knotmeter, also) is always cheap insurance.