25.5 plumbing questions

[Zephyr-Jeffer]

I'm trying to understand the plumbing inside the '84 25.5 of mine.
The documents I have found here show a very crude, single-line diagram.
So yesterday I visited her (in cradle) and see that the galley sink drain goes straight down into the cabin sole - there is a shut-off valve. Where does that drain exit? Out the starboard side?
Also, in the floor, about mid ship, a large section of flooring lifts up and you see where the keel bolts attach. In that space (which is clean as new) there is a plastic hose - maybe 1/2" ID, what's that doing? should a bilge pump be attached to it?
Are there better plumbing documents out there?

thanks

 

[twodzusfittings]

Your Galley sink drains through a thru hull which should have a ball valve on the inside at the end of the drain hose. This drains straight into the water below. The smaller hose in the bilge should have a bilge pump attached. Lift up the smaller of the two boards (unless yours is one long solid peice) to see if it exists. This drains to a thru hull under the sink in the v birth, across from the head. If you look outside there should be two thru hulls. One for the sink, the other for the bilge. Your ice box also drains into the bilge area.

 

[Justin_NSA]

Somewhat related (drains) - the cockpit drains on the 25.5, like a lot of boats, can plug up with debris and flood the cockpit in heavy rains. There was another thread on this, but I don't think anyone posted any cool mods other than placing extra straining material in front of them.

 

[Crazy Dave Condon]

Most of the sink drains on trailerables were discharged thru a thru hull above the water line vs. thru a ball valve unless going thru the hull itself or near the waterline. I have seen bilge pumps with a line going up thru a discharge thru hull above the water line but most had a loop in it to prevent back flow in the event the discharge was close to the waterline. In the case of the sink, it is much higher and the idea of water back up was not an issue thus no loop in that discharge line.