On my 1995 2320 I have the hatch in the same location. It has a rim drain with a 90 fitting and a small diameter hose that drains overboard on starboard side above the waterline. The drain plugs easily. No idea how to access the hull interior here to change plastic thru hull or hose if need be.
The well itself is only about 12" depth and fairly useless for storage or as a fishbox. No insulation and small. On the vertical part of well facing the stern there is a round hatch - the cheap push on type. When you open the round hatch you can contort your body to reach down to a thru-hull with a seacock that is basically right under the tank. The well has a drain at the bottom..also like 1/2 inch diameter which is connected to the seacock with hose. Fish scales and such clog this up right quick.
I guess it looks exactly the same as Mike's 2000 in this thread....i just have an on deck bait tank immediately aft of the well.
As a westcoaster I always figured this was some sort of east coast livewell type setup. Weird, though. If I filled the well with water there would be no way to open the hatch and close the seacock without filling the bilge with water from the well. I've always just scratched my head about this.
Ideally, I'd like to cut out the existing fiberglass well and replace it with a much deeper insulated fishbox. I guess if I could, I would plug the thru-hull that is on the centerline and have the new fishbox drain overboard above (or at) the waterline with a macerator pump. All it takes is money I think.
I'll try to take a photo of my setup to add to the mystery of 2320 storage evolution over the years.