Hey Brandon, the Seafari 25 is a totally different animal relative to the 20. The stepdown on the 20 inner liner rests on top of the 2x4 keelson, so there's a couple of inches vertical clearance between hull and deck. It's basically wide open; I've hosed out the open compartment under the front hatch under the bunks and any water sprayed in there runs back to the transom immediately if boat is on trailer with bow raised up. Some later models ('74 & later?) had a fancy gel coated box under front hatch so you couldn't really see into bilge in there. Is your boat open to the bilge up under that forward hatch? Maybe there's some sort of bulkhead up there, but I would think they would want to leave it open for ventilation so as not to trap any gas fumes up there. Maybe you need to run a roto-rooter thru the bilge to clean out any rats nests or misc debris!
Denny