Indonesia lies in the middle of the large marine Indo-Pacific basin. This region extends from the Indian Ocean waters off East Africa all the way to the Hawaiian and Marquesas Islands in the Eastern South Pacific. The central area, the waters around the Indonesian and Philippine Islands, is the least well-known, and much scientific work still needs to be done. In tropical waters, where the temperature and salinity are right, corals seem to "blossom" into gardens, with an amazing variety of forms and colors.
Growing corals form reefs, functioning as homes for whole communities of marine life, they also provide nourishment and nurseries for thousands of fish, shellfish, sponges, crayfish and marine plants, while protecting shorelines and creating islands in the process.
Whether scuba diving (snorkeling) or deep-diving with breathing equipment, or exploring a reef, it is an unforgettable experience. Indonesia's smaller islands are often surrounded by reefs, and many are inaccessible and still undeveloped as far as marine tourism is concerned. The single exception is Pulau Putri in the Thousand Islands, northwest of Jakarta. Other good places: Pulau Peucang and Panaitan off Java's western most peninsula in the Ujung Kulon Reserve; coral reefs off the Tangkoko Batuangus Reserve in North Sulawesi; Pulau Kasa near Ambon in Maluku, off the Bali Barat Reserve, in Bali. The Riau archipelago also offers some excitement to divers of a different kind: coral reefs are here combined with the interest of exploring sunken ships and wrecks from World War II.
Indonesia is rich in ornamental fish species, which are exported to the United States, Japan and Europe. Among these beautiful marine aquarium fish species are the amphiprion, the dascyllus, the red colored labrida and the gorisaygula, found plenty in the waters around the bali strait. The balistoides niger, is found in abundance in north Sulawesi.
Apart from fish, the waters around many islands, especially in the more virgin areas in the eastern parts of the archipelago, offer a rich variety of conches and shells and one of the world's most beautiful conches, the so called "Glory of the Sea".
In waters around nature reserves, however, the collecting of fish, shells and other objects of marine life is prohibited.