Northeast of Fajardo off the coast of Puerto Rico, the snorkeling off Icacos Island (aka Cayo Icacos) is known for its water clarity. It is part of the Cordillera Keys Nature Reserve.
To reach Puerto Rico by air, fly into Luis Munoz Marin International Airport (SJU). To reach the Icacos Island snorkeling, you will need to use the 10 minute boat from Fajardo.
Overall, Icacos Island is the 8th most popular snorkel dive spot of all 17 snorkeling dives in Puerto Rico.