been going to the bahamas in october for years...stuart coves's trips are good...boat trip,fairly deep water( i believe so people cant touch the reef ) you see where some old james bond movies were filmed....after you leave the reef you anchor in another spot where they drop in a bait box,everyone hangs on to a rope at the surface (so you dont have to kick and splash and draw their attention)and you watch dozens of reef sharks feeding below you...and some get pretty damn close to you...pretty cool....coming in on a cruise ship i dont know what your schedule will be...new providence is a small island but cove's dock is at the complete opposite corner of the island from where the ships dock so make sure you have enough time....i actually prefer the reefs around rose island (just east of paradise island,and closer to where you'll be docked)...these are shallow reefs where you're on your own and can just wade out to them off the beach...its another boat trip with lunch at the beach so anyone in your group thats not into snorkling can swim,hang on the beach or drink at the bar...the "booze cruise" trips the snorkling isnt very good but you will return wasted...excursions to exuma on Powerboat adventures are excellent all-day trips ,they are a lot of money (but worth it if this is your first trip to the tropics and want to experience lots of stuff)...the drift snorkling is ok but not excellent but again is part of a full day trip with other stuff to do...again ,dont know your time constraints or budget...do yourself a favor and buy a decent snorkel with a check valve ...its worth a $50 investment to keep from swallowing half the atlantic,and will make the experience MUCH better...your own mask that fits properly (and some anti-fog solution)wouldnt hurt either....avoid nassau divers,their boat was a POS...one engine wasnt running right and was dumping diesel fuel out the exhaust...i was on a shallow dive but my wife was trying to snorkel in an oil slick and got REALLY nauseaus...have a blast...