Simple
Flexible tubing for this job is available at West Marine, Boat/US, or any hardware store. I assume that all four holes (two in hull and two in cockpit) have nipples that are accessible from the cabin. Mine are offset about 4 inches so I have to bend the tubing. I think the tubing diameter is 1/2" or 5/8". It is cheap enough to buy a few sections and see which one fits the best. Also, make sure you prebend the tubing. I let mine soak in boiling water. I then pull it out and form the two bends. Otherwise, if you try to bend them on the boat, they tend to kink and junk gets caught in there. If fact, the tubing I bought from WM has wire in the jacket. It resists kinks even more. Let me know if you have any questions. Good Luck, Craig craig@110.net
