On the drive to work this am I pondered the same problem. I have put quantities of fish on deck, dragged them to the side and behind, and stuffed them under my knees; all unsatisfactory solutions.
I was imagining some barge to tow along. Maybe an inflatable or a Mini-Auk. I am intimidated by the SOF process, so maybe I'll make something like that.
I have reservations about the accessibility of a rear hatch (expecially when wrestling a decent fish in marginal conditions). I don't think the weight of a flooded compartment is a direct problem, but wouldn't the lack of bouyancy behind affect the trim and raise the bow?
Its nice to see a fishing issue on this board.
Mike