Can't say for sure, but will offer the starboard seat base in the cockpit of our 348 comes out. Sounds like a similar situation. I have to remove a bunch of screws in the floor of it, break the caulk seal where it meets the main deck and take out the cushion seatback and base. Once that's done the whole L-shaped base of the locker comes up and out. It's a BIG piece and a bit unweildy for one person, but I got it out by myself.
Seating removed, floor panel still in place:

Panel removed: (and water heater being removed)

I discovered this by asking the factory how to get at the danged hot water heater. It was a revelation knowing that WHOLE section could come up and out. Might be worth inquiring of the factory about it.
boating@fourwinns.com is my usual source for getting questions answered. It's always good to go through a local dealer first, but sometimes they just don't have a clue.