Independent water excursion companies heavily ply the beaches looking for tourists to potentially "take advantage of" while "taking advantage of" their recreation services. These opportunities can be a blessing if you're interested; a curse if you're not looking to be bothered.
Water activities include wave runners, rides on water wienees, parasailing, snorkeling or fishing runs and glass-bottomed boat rides. As you might expect, prices vary based on the rep you're dealing with and you're willingness to play the bargaining game. Sales pitches I heard included 30-minute wave runner rentals for $30 up to $125 larger-scale boating trips which also included lunch and drinks.
On the trip when I went with four other friends, three of us decided to try parasailing and we got a "group rate discount" of $50 each for the 15-minute or so ride. (Actually, I couldn't tell you how long we stayed up, but I wish it never would have ended!) You're shuttled from the beach to a floating dock somewhere out in the bay where you harness up and take off. For this, my first and only attempt at trying the sport, I can't imagine a better place to have done it than in the Bahamas! The beautiful shallow turquoise waters and random white sand bars were beyond description...kind of like that Bahamas Tourism TV commercial where the water plane lands out in the middle of no where and all the bikini-clad honies are just waiting...unfortunately, of which I found/saw none this adventure.
This is/was an experience I'm not sure you could put a $-value on no matter what they're asking...cause it'll be worth more! And if there's such thing as advice from a first/one-timer, try to relax in the harness or the muscle tenseness from soaring like a bird will net soreness later. Your mouth will also likely be wide open, but don't gasp for air. There's something about the thick salty air coupled with the experience and constrictiveness of your confines that can all but take your breath away.
Calmy back at the beach, snorkeling is readily available though you're really not going to see a lot close by. Unless you plan on taking one of the larger excursions which takes you further out to deeper waters, leave the flippers at home. You can walk forever in the shallow waters needing nothing more than your mask and tube. Just be aware that all of that "bent over" exposure to your back can get you roasted fairly quickly.
AS A PRECAUTION - Especially if traveling alone, never take an excursion or venture too far on land or water and leave your things "unguarded" on the beach. There's a lot of foot traffic...and it's not like this place owes you any security or duty of monitoring your things since you're NOT an offcial guest.