I also wanted to contribute our experience on the 3-day in Nassau last Dec.
We did the glass bottomed boat (which I don't recommend but will leave detail for another thread), and returned to the ship immediately thereafter. DS 5 enjoyed the Mickey pool, which was incredibly empty. No scramble for lounge chairs, less risk of an "accident" that would close the pool. . . LOL. . . .I have been reading the swimmie diapers thread with great interest!
We enjoyed a very relaxing afternoon and did not participate in any organized activities until after our early dinner seating. Just my thoughts on the idea of doing "nothing."