The way the flight decks are marked, they are single-spot, meaning one aircraft at a time. That said, if you visit the New Jersey, the SH-2 they have aboard is actually next to the barrels of turret 3, so they could have potentially folded and stashed them there. That said, it's really bad to leave an aircraft out on the flight deck of anything closer to the water than a carrier. The aircraft have to be sprayed down with fresh water every couple hours to prevent corrosion. I don't know if that practice was in place while the battleships still roamed the seas, or if their flight decks were elevated enough, but it's possible.
Groot