Great idea, I was cringing (sp?) at the thought of buying a pump. They're expensive.

I have an idea. I believe I heard it somewhere on this board, but why not put a hole in the top of the kayak under the compass mounting plate. There could be grooves in the bottom of the compass mounting plate to let the water flow out the sides of the plate and down the side of the boat, but you wouldn't see the outlet hole.

Also, if you make the inlet go in the bottom, then out the top of the pump you won't have the water going back and forth at the tee. It will flow in one direction only. Plus you won't have the restriction of a tee.

I agree that you would need a long bushing, or a couple of supports for the piston rod so it would go in straight and not bind up.

Wouldn't you need a hole in the aft end of the pump to let the air in the area between the piston and the aft end go in and out and not build up pressure/vacuum?

Dale