I'm currently replacing the hoses on my scuppers to through hulls. I found some tubing at west marine that's the right size and much beefier than the original. I don't have the part number in front of me but there's a 140 in the title and it's white. I plan on putting 2 stainless hose clamps per end for safety sake and having the proper plugs and a mallet somewhere easily accessible. I'm not going to add valves.

:: Don't waste your money on expensive valves you will
:: never use. These hoses are usually heavy duty and are
:: under very little pressure (1/2 psi).

:: Change the hose clamps once in awhile and check that the
:: through-hull is bronze not brass. Electrolysis can eat
:: away the zinc and leave the copper very weak. Replace
:: the t-hull and hose every 10 yrs. or so. If you are
:: nervous

:: carry a spare piece of hose.
::
:: :: Steve,
:: ::
:: :: It's typically not the thru hull fitting itself that
:: :: fails, but rather a hose or hose clamp that services the
:: :: thru hull fitting. Since the thru hull fitting sits
:: :: below the waterline, if there is a failure in any of the
:: :: hoses that service the fitting, water will come in. The
:: :: seacock is there so you can shut off that flow of water.
:: :: They're a very worthwhile investment, so be glad you
:: :: have them. You should open and close the valves every
:: :: few months to ensure proper operation, and replace them
:: :: if they don't operate properly, or if they show signs of
:: :: corrosion.
:: ::

:: :: -Claude

:: ::
:: :: :: Hi
:: ::
:: :: :: I have large valves attached to each of my cockpit drain
:: :: :: hose too and I have sat in the cabin looking at them
:: :: :: thinking what they might be used for. (When you might
:: :: :: want to shut them.) I can not see how they can protect
:: :: :: from though-the-hull failures. If the drain
:: :: :: through-the-hull fails, it will be of concern if it is
:: :: :: outside the hosing system--in which case shutting the
:: :: :: the valve would be pointless. If the cockpit is awash
:: :: :: with a wave, there is no need to close the valve then
:: :: :: either. The only reason I could see to close the valve
:: :: :: would be to take a bath in the cockpit, but I have
:: :: :: better places to that.
:: ::
:: :: :: Someone spent some time and some money to install these
:: :: :: things.
:: ::
:: :: :: I do not under stand why. Could someone explain this?