Pas I would agree with you if he had a cruiser but it's an Model 1800, 18 foot boat. Probably a bowrider. Only one bildge pump in the engine compartment. The ski locker is in the floor between the port and starboard seats.
pinchio are there any drains on either side of he boat that line up with the location of the locker? If so try running the fish tape from the outside.
1997 2400 SCR
5.7 Vortec / Bravo 2