Bunaken is an island of 8km2 which gave its name to the national park of Bunaken. This last one was created in 1991, its total surface is 890,65 km ², among which 97 % is constituted by water. The remaining 3 % consist essentially of five islands: Bunaken, Siladen, Manado Tua, Mantehage and Nain.
The visibility varies from 35 to 40 meters and the temperature between 27 and 29 °C.
Bunaken owns one of the most important marine biodiversity of the world. So, The national park possesses about 70 species of corals, versus 10 species in the Hawaiian Islands. Not more than 2,500 species of fishes are found here, almost 70 % of all the listed species of fishes in the West of the Pacific Ocean.
The eastern side of Bunaken Island offers superb wall diving and excellent snorkeling. The vertical wall has many cracks and small caves and is covered with soft and hard corals, gorgonians and huge sponges. Fishes are abundant and you can expect to see many different species. Possible encounters include turtles,whitetip and blacktip reef sharks and stingrays.
The southern side of the island has beautiful coral slopes in a deep calm bay, as well as vertical winding walls on the sides of the bay. This side of the island has a high diversity of fishes, corals and sponges, and there are many good spots for snorkeling. The Lekuan spots are frequently rated as the best sites in the park, and they certainly made Bunaken famous for diving. There are huge schools of fusiliers, pyramid butterflyfishes, bannerfishes and damselfishes – in fact on some dives there is just so much fish that you cannot see the reef wall. Frequently you will also bump into reef sharks, napoleon wrasses, hawksbill and green turtles, great barracudas, eagle rays, snappers, scorpionfishes and leaf fishes.
The dive sites on the western and northern sides of Bunaken are vertical walls abundant with reef fishes, lobsters, whip corals and giant gorgonians. You might also see large emperors, red snappers, groupers, dogtooth tuna, eagle rays, giant trevally, whitetip reef sharks, turtles and barracudas. Even manta rays and whalesharks are said to have been seen around Bunaken.