You mean under that dirty deck hatch? It is a fish box. I don't know how big it is, but I would guess it would hold 16 - 20 28" rockfish. HeHe it is perfect for doormat flounders.
My 2320 DVSC, as opposed to the new design (which makes mine a classic 8) ) is much deeper in the bilge. There's room for more boxes, but I don't want to loose that much foam to put them in!