We just returned from a week aboard Aqua Cat:
http://www.aquacatcruises.com/
While we had heard many rave reviews from others who had cruised her, our expectations were far surpassed!
Wall diving (more should be made of the fact that the walls off the Exuma Islands start at 60'), wreck, shark feeding, night diving and blue hole.
Definitely the best Bahama experience we've ever had! We were certainly blessed with an extraordinary captain and crew. The crew had an 10+ attitude for the entire week. We both shed a few tears when we arrived back in Nassau. Goin to do it again next year!
Tom & Therisa Stack