On the west coast of Tenerife, the snorkeling at Los Gigantes is known for seawater pools with diverse habitat. There is a fee to access these seawater pools, which are best just before low tide.
Overall, the snorkeling around Tenerife is good year-round and the water temperature is pretty consistent. You may want a thin neoprene shirt during winter months. During certain times of year, there may be opportunties to snorkel with either pilot whales or with butterfly rays in the waters of Tenerife, so make sure to check with the dive shops for more info. Also, the waters of Tenerife are frequented by five types of turtles including loggerhead turtles, green sea turtles, leatherback turtles, hawksbill turtles and olive ridley turtles.
Since the Canary Islands are actually part of Spain, the best way to fly to the islands is through an airport in Spain. There are flights to all of the main Canary Islands directly from one Spanish airport or another. Of course, Madrid offers the best connections. Presently, there are not direct flights from the USA to the Canary Islands. Once in the Canary Islands, the best way to go between islands is still by inter-island flights. There are some boat services that do go between the islands as well. TIP: For your safety, most of the Tenerife snorkeling dive sites require snorkelers to have a diver-down flag marker. The waters around Tenerife are very popular with windsurfers and boaters, which has resulted in some snorkeler deaths over the past few years.
Overall, Los Gigantes is the 15th most popular snorkel dive spot of all 39 snorkeling dives in Canary Islands.