Southwest of Biloxi and southeast of Gulfport, the snorkeling off Ship Island offers a surprising amount of marine life. While the Ship Island snorkeling is not known for its water clarity, you are still likely to encounter Mississipi stingrays, redfish, seargeant majors, damselfish and plenty of crabs. Also, keep your eyes out for blacktipped reef sharks.
West Ship Island is part of the Gulf Islands National Seashore and is home to Fort Massachusetts (circa 1868). It is about 11 miles offshore of Gulfport, and is accessible by ferry boat from Gulfport.