Snorkeling on your own!
If you are not a big time snorkeler and are happy with a shallow reef and a few fish, here's a few places to try.
We brought our own gear (mask, snorkel, pfd) with us. The snorkel and mask cost $19 at sports authority and the pfd's were $20 at Namco. By bring our own, we could explore the beaches and snorkel at any spot that looked interesting.
Westwind II Snorkeling
There is some sea grass and a few fish in the area marked as the Westwind II swimming area. But a better place is to walk next door to the Radisson's beach. There are 3 small reefs a short distance from shore. The reefs appear to be manmade but there's enough to see. There were Sargent Majors, Jewel fish and Angel fish. Also some sea anemones. We were told that a barracuda and a small octopus were spotted the week before but we didn't see them.
Orange Hill Beach
This is a small beach off the side of the road past Sandyport and before the Love beach area. There was not much hard coral here. The water was shallow and calm. We stopped because we saw a few others snorkeling here. There were a few sea anemones and some small fish.
Honeymoon Cove at Atlantis
We walked here from the public beach access next door to the old Sheraton. The Atlantis beach is private but nobody bothered us. Walk all the way down the beach and then across the bridge to honeymoon cove. About 3/4 around the cove is a good sized coral reef with a deep cut. There were a few large fish and some smaller ones around the reef. The main Atlantis beaches are clean but crowded. This one is a bit of a walk and was nearly empty.
We had fun at these smaller reefs but they didn't compare to the Sea Island Adventures Rose Island trip we took. These are fine for an hour or two and for some practice before you head out on a snorkeling tour. They are also great if you want to hit the beach for a couple of hours either before or after some other exploring of the island.