Thru-hull questions

[dbetterred]

My 1984 v20 has 2 below water line thru-hulls on each side. One is for the cockpit drain and the other is for the in floor fishbox overflow. the fishbox thru-hull is one size smaller than the floor drain. Do you guys know what size fittings they are? I was thinking 3/4 or 1 inch for the fishbox and 1 or 1 1/8 inch for the floor.
I don't want to order the wrong size and be screwed, I'm already behind schedule for the first launch!
Are the thru-hulls size determined by inside diameter, like hose? Or by the size of the hose that fits the fitting?

Thanks in advance!

[RWilson2526]

I'm nearly positive that they are sized by the hose barb that 's on the through hull....so a 1" through hull has a hose barb that fits 1" id tubing.
The ones that drain my cockpit are 1". you should just be able measure the id of the tubing that goes to the one you want to replace and order it that way.

[dbetterred]

Good deal, that makes sense to me!
Thanks!