There are few famous locations in sri lanka for snorkeling, Hikkaduwa, Unawatuna and Trincomalee.
Hikkaduwa is the best place for beginners, kids & especially who do not wish to swim much. On the first step in to the water at Hikkaduwa Marine Park you have the ability to feed fish, schooling fish will found few meters away from beach and the maximum depth is around 3m and average is 1.5m. While snorkeling you can swim with two giant turtles “Rossi” & “Victoria”.
Equipment rent and guiding can be arranged upon your request.
Trincomalee is a superb place to see corals and small sharks and other sea creatures, actually the location is Pigeons Island at Nilaweli few Km to the north from Trincomalee. There are two sides at the island, snorkeling and bath. we always provide a guide and life jackets (if you need). The depth varies from 2 – 6 m. this is a must visit location in Sri Lanka
Mannar and around passikuda also have some reefs not exposed to tourists yet.