Hatch Cover
I read about a new 228 with an F250 being too heavy at the stern so water came in the scuppers. Grady moved the main tank foward and now the space for the aux. tank was aft. I have an '02 228 Seafarer w/ an F250 and though water does not come in my scuppers I still thought to swap the tanks position in hopes of better handling. Then it occurred to me that I could put a hinged lid on the aux tank space and use it for a fish box. I called Grady and they said don't do it. Gradys are designed so water can not get into the bilge and opening up this area would violate this watertight integrity. Besides, my boat handles great the way it it.
Still, if you were careful to seal the area and make provisions for draining or pumping out it would seem OK to me.
Good Luck,
Dan