In the South Atlantic, the snorkeling at St Helena Island is well known for about a dozen dive spots. This is a dry volcanic island with few sandy beaches. While snorkeling off St Helena Island, you may encounter hawkfish, wrasse, parrotfish, whale sharks, hawksbill turtles and green sea turtles (December to June). The water depth ranges from 15 feet to 100 feet deep, and the water temperature ranges from 65F to 75F.
The best snorkeling is found off the rocky reefs near Jamestown on the leeward side to avoid currents. Some of the best St Helena Island snorkeling spots include Lemon Valley, Buttermilk Point, Cat Island and Thompsons Valley Island. From June to December, there are some snorkel boats that head out to encounter whale sharks.
There isn't much of a tourism industry on St Helena Island. You'll be pretty much on your own for gear and arranging to visit any of the snorkeling dive sites.
In order to visit St Helena Island, you will need to apply for an entry permit at least one month prior to arrival that requires proof of travel and medical insurance. The usual route to the island is the nine hour flight from Brize Norton, UK.
Overall, St Helena Island is the 2nd most popular snorkel dive spot of all 2 snorkeling dives in Saint Helena - Ascension.