I’m not sure whether new gasket will fix the leak either but the leak appears to be between the gasket and the fiberglass. The water would have to be deep to go over the top of the gasket and between the bottom of the seat. There is a ring on the underneath side of the seat where the seat makes contact with the top of the gasket. So the water has just about Gotta be leaking where it contacts the fiberglass, where the gasket slides on to the edge around the cutout itself. I would like to try a new gasket hopefully it will fix the water leak in that compartment.