Nik's Mom - My husband and I were on the Wonder two weeks ago and we did Atlantis on our own. We had so much fun! We took the water taxi, which I understand is much less of a hassle than a cab (and it's prettier). We spent about 3 - 4 hours just walking around the grounds. There is so much to see! It is $29/person to walk through "The Dig" but honestly we saw so much marine life just walking around the grounds, we didn't feel the need to pay to see more. The aquarium before you enter The Dig is amazing - we saw a manta ray! - and then there are several others winding around the pools and restaurants. We saw several types of sharks, stingrays, baracuda, and all sorts of tropical fish without paying a dime. We also walked out onto the beach, which I'm not sure we were supposed to do, but no one said anything. Maybe because we weren't carrying towels and beach bags and looked like we were coming for the day, I don't know? Anyway, there are also a lot of nice stores to walk around there as well. We really, really enjoyed it! And we were back on the ship in time for a late lunch and a cocktail by the pool.
As far as other things to do in Nassau, the family we sat with at dinner did the stingray excursion and the kids loved it. We walked to the Straw Market and it was mobbed and hot and we turned around and left. After seeing the beach at Atlantis, I kind of wish we had done one of the snorkeling excursions, but now I have a reason to go back!!