I believe they all go out of Nassau now. They may keep 1 boat in Freeport, but I think it is dedicated to Boy Scout trips. As for my comments on "typical Bahamas" environment, the dive sites, especially, in & around the populated areas show signs of being "over- dove" (reef damage & such). You will likely see all the "regular cast" of critters common to the Caribbean. I am not saying it is bad,... Just that I have done 6 diving trips to the Bahamas in the last several years & after some of the places I've dove recently (Malaysia (Sipadan) last year & just got back from the Galapagos), the Bahamas just can't hold a candle to them. Its all in perspective, I guess. The shark dives are kind of cool, but once you've seen it once, you have pretty much seen it all. It is generally easy diving, nothing too advanced, that I've ever seen. For the March time frame, you'll probably want to look at a 5mm wetsuit in the least, especially if you tend to get cold easily. The waters will still be quite cool at that time. I dove the very southern Bahamas (San Salvador area) a few years ago in late April & a 3mm was almost not enough.