Don't know if you're doin the 3 or 4 day to Bahamas. If it's the 4 and you stop in Freeport, I'd consider doin the glass bottom boat there since there's NOTHING at the pier. I've been on it, and while I've been on several better, it was nice for Freeport. Nassau offers many better things to do other than that excursion.
Thanks for the tip, I think we decided on the glass bottom boat in Freeport (my son wants that over the beach party) and the Atlantis tour in Nassau, followed by the walking tour and seeing what museums in that area are open. We're not into water sports of scuba so I think this will do for us.