[ocuyler]

Been there, done that. I had the hatch off when I did it and it was sill an PITA. However, by attaching a rope with duct tape (very securely) and pulling it through, you'll be able to pull another hose back up through there inversely. If you have to warm up or lube up the hose, fine, but don't let the rope become disconnected from the hose. Try everything befor cutting holes in the boat. Mine was only 12 years old and was cracked and leaking. Have fun!