The Island's underwater scenery is as spectacular as its picturesque landscape inland. Beneath its Indian Ocean waters lie submarine fairylands of coloured coral, Jewelhued tropical fish and mysterious submerged shipwrecks, which promise memorable sightseeing and exciting adventure for snorkelers and scuba divers. Its classic tropical location 5 to 9 degrees north of the equator, ensures perenially warm seas, which remain at an inviting temperature of around 27C, in season. The two monsoons; northwest and southwest govern the sea conditions and calm seas and clear water are experienced from November to April along the southern and western coasts and from April to Oktober in the east.
Sri Lanka offers a variety Diving of reef types; coral banks, sandstone platforms and rock cliffs and boulders that are found from near shore to several kilometers offshore. Extensive shallow offshore coral banks occur in Vankalai, Silavathurai and Arippu and along the Kalpitiya Peninsula in the Gulf of Mannar. Diving Coral reefs from the Kalpitiya Peninsula to Negombo are located about 15 kilometers offshore and in deeper water at a depth of about 20 meters. The majority of reefs in the west are sandstone platforms whilst offshore patch reefs similar to those found in Negombo occur off the coast of Colombo between Mt.Lavinia and Galle Face at a distance of about 20 kilometers offshore. Rock boulder reefs Diving are common in the southwestern and southern coasts from Bentota to Tangalle. There are many small fringing coral reefs along the southern coast, the well know coral areas are at Hikkaduwa, Rumassala in Galle, Unwatuna, Weligama, Matara and in Tangalle. In the east coast there are several coral reefs from Nilaveli to the Trincomalee harbor and from Foul Point to Kalmunai located south of Batticola. Reefs from Kalmunai to the Great and Little Basses off the coast of Yala National Park are mainly rock boulder reefs.
Fringing coral reefs Diving are found in the Palk Strait and Palk Bay along the northern and western shores of the Jaffna Peninsula. About 200 species of corals are found in Sri Lanka. Generally they can be classified into five different growth forms; branching, tabulate, foliose, encrusting and massive. Extensive reef formatios such as in the Gulf of Mannar are formed by branching, tabulate and foliose corals. Fish are abundant on most offshore reefs and more than 500 species have been identified. They vary from small damselfish that dart about among coral branches to large parrotfish, jacks and groupers. Sri Lanka has thirty five species of butterfly fish and three species of large angelfish. The best reefs to see large fish are the ones offshore and in relatively remote areas where fishing pressure is low. Sharks are generally uncommon on our reefs and the only area where blacktip sharks can be seen regularly is among the shallow coral reefs inthe Gulf of Mannar.
Offshore reefs in Negombo, Colombo, Beruwala, and Bentota along the western coast have schools of larger fish and offer good photo opportunities but are accessible to scuba divers. In the south the best site for diving and underwater photography is the Great and Little Basses reefs off the coast of Runhuna National Park. These are accessible only for short periods in October and April during the intermonsoon. There are several good dive sites in the east for fish photography and the most popular site is the Pigeon Island National Park in Nilaveli. Shipwrecks also offer good diving, especially for fish photography. There are many dotted along the southern waters and in the east including the British aircraft carrier Hermes located off the coast of Batticoloa. Most of the wrecks and offshore sites are accessible by scuba Diving.
Sri Lanka has four coral reef protected areas; Bar Reef, Hikkaduwa, Rumassala and Pigeon Islands declared under the Fauna and Flora Protection Ordinance and are managed by the Department of Wildlife Conservation. The Bar Reef Marine Sanctuary located off the coast of the Kalpitiya Peninsula is the largest and encompasses an area of 306 square kilometers. The Hikaduwa National Park in the southwest is the oldest marine protected area. The Rumassala Marine Sanctuary in Galle is a small fringing reef within the Galle Bay. Pigeon Islands National park in Nilaveli in the Trincomalee District is the only coral reef protected area in the east. All underwater enthusiasts, whether experienced divers or just first time submarine sightseers, are ensured of a highly rewarding and enjoyable experience in Sri Lanka’s diving paradise.