I have a 24' Beachcraft which I was told is actually a Tolly Hull. I have a washdown pump that is now conncted to the I/O fresh water inlet, which I do not like cause you can only use the pump when the engine is pumping. The pump is now located very near the stern next to then engine, under the floorboards. I want to install a thru hull fitting for the washdown pump and can't decide where to locate the fitting. I am a little nervous about drilling a 3/4" hole in the wrong spot. I guess these are the choices, thru the bottom which seems very thick..I was told that these Beechcraft/tolleys had solid fiberglass bottoms. Thru the side below the waterline, thru the transome below the waterline. I know that I need to put in a ballcock valve in case of a broken hose
I would use bronze thru-hull on bottom with bronze valve easily acessable. Mount the pump above thru-hull and below water line if possible for easy priming. Run hose from pump to valve uphill with no low spots to avoid vapor lock. Good Luck.