I have a 1990 231, and the scupper on the starboard side of the transon is a drain for the fuel tank compartment. This scupper was leaking a small amount, allowing sea water to enter the tank compartment. The tank is leaking fuel out of this scupper now, and I am going to replace the tank. When I finish the tank replacement, I intend to replace this scupper with a regular removable plug. I am pretty sure that if this scupper where to fail completly, the fuel tank compartment could fill to the boats waterline with seawater. Any one else had a similar failure?