Sangalaki Island

  Celebes Sea near Tanjung Redeb, Indonesia


Part of the Marine Heritage Park, Sangalaki Island is one of the richest diving grounds in Indonesia, which is saying quite a lot! The uninhabited island is surrounded by a wide lagoon and shallow reefs extending well out to sea. The currents vary from gentle to moderately strong, there are no walls, and little drift, just an abundance of rare and exotic marine life, including giant turtles, and the famous schools of Manta rays, or devil-fish.

The majestic Manta rays have been aptly compared to stealth bombers. This is especially true of the glistening all black ones which can be seen here at Sangalaki Island. They usually swim in the upper waters, somersaulting and gambolling, their massive wings breaking the water as they soar into the air and come crashing loudly down into the water so snorkelling or free diving is a wonderful way to observe them, and they will often come over to greet you. These amazing creatures are strong, swift swimmers and may even cross the open ocean, their sandpaper skin and wide wingspan attract Remora and other parasites, which they remove regularly at reef-side "cleaning stations" as well as by their crashing dives. They live off the plankton which they filter through the many rows of teeth on their lower jaw. These are so plentiful around Sangalaki that the Mantas rarely have to seek in deeper waters for food, which is probably why they can be found here in large numbers throughout the year.

Giant Green Turtles nest on the sandy beach all year round and you can see them in all sizes swimming under ledges and in the gullies throughout the reef. The rare Hawskbill turtle can also be found here and there have been occasional sightings of the Leatherback Turtle as well.

There are over 500 varieties of soft and hard coral in the reefs surrounding the island (the entire Caribbean has only 67) and the invertebrate and fish life of all sizes is just as prolific, so you ned not fear running out of things to see. The reef is riddled with small ridges and gullies which form individual mini ecosystems, each with its own population of exotic fish and coral including stingrays, cuttlefish, batfish, barracuda, triggerfish, angel fish, and a variety of grouper.

There is no accommodation on the island itself, but the nearby resorts at Derawan and Maratua Islands have regular diving excursions to Sangalaki, and it is well worth taking a day to enjoy the high quality dive sites here.

Sangalaki Island Dive Sites
Sangalaki Island Dive Sites

Notable Dive Sites

Coral Gardens: Just west of the small channel is an undulating bed of brightly coloured hard and soft corals shelving gradually to 27m before becoming sandy. Among other beauties you can see sponges, giant sea fans, purple carpet anemones, feather stars and gorgonians, and giant clams, as well as cuttlefish and many species of graceful angelfish and butterfly fish darting in and out among them. From here you can drift through Turtle Town and on to Sandy Ridge.

Turtle Town: Lurking under overhanging rock shelters and in the coral gullies, you can find numerous turtles of all sizes. The giant Green Turtle is the most common, but you can also find other species. They breed all year round and can be seen playing and hunting in the shadowy depths amongst the colourful corals and a plenitude of other fish.

Sandy Ridge: Famous for its blue-ribbon eels, this beautiful dive site abounds in small sharks and shoals of fusiliers, snapper, catfish and jacks. A variety of soft corals and sponges can be seen, including lettuce coral, tube coral, and even some Gorgonian sea fans. The amazing Giant Clam can be seen on the seabed, along with lobsters and other crustaceans.

Manta Run, Manta Parade, Manta Avenue: On the northwest side, you can explore the corals at 28m while Manta rays circle overhead. Expect to encounter groups of 20 to 50 of these majestic creatures. They are wonderful in small numbers, but seeing them en masse like this is an awesome experience. It is not uncommon while admiring the corals and sponges, and observing the unique nudibranches, Coral Trout, orange-striped triggerfish and barramundi to see the shadow of a ray hovering overhead.

Manta Cleaning Station: The sandpaper texture of the Manta ray's skin offers a perfect host for remoras and other parasitic fish. Just off the edge of the reef the Manta rays queue at the cleaning station where cleaner fish and small wrasse pick off these parasites and other debris from their gills and fins. It is a fascinating site to see these magnificent creatures waiting patiently while the cleaning takes place.

Best Time to Visit

Food for the various species is so plentiful, and the water temperature is so consistent that you can dive all year round and expect to see large quantities and variety of most species. Even the Manta rays and giant turtles are permanent residents. The turtles and rays seem to be especially active at the full moon so you might want to take that into consideration.

Although visibility is reduced during the rainy season from November to March it is still generally over 20m.


The tiny island of Sangalaki in the Derawan Archipelago, East Kalimantan is a protected Marine Park, and is under consideration as a UNESCO World Heritage Site. Its pristine reefs have been protected from reef bombing and cyanide fishing by its remote location, and it is the home to a wide variety of marine life, including over 500 types of hard and soft coral, and an abundance of fish. It is one of the most important ecological hotspots in the world.

The endangered Green Turtle lay their eggs on its tranquil beaches all year round. For some years the vulnerable eggs were subject to the predations of a large population of rats and monitor lizards. Although the monitor lizards are native to the island, the rats probably arrived either with tourists, or with the building materials and supplies for the Dive Resort and the Turtle Foundation Research station. With abundant food and no natural predators, they multiplied rapidly and feasted on the vulnerable turtle eggs and hatchlings. A carefully planned strategy for exterminating the rats without harming any other wildlife was carried out in 2001-2002 and the rat population has been reduced to zero.

The Turtle Foundation has actively sought to protect the eggs and hatchlings from harm and maintains a research station and hatchery at Sangalaki Island. In the 1970s locals report seeing over 2,000 nests on the islands during the breeding season. In recent years these numbers have declined dramatically, to as few as 150 nests, and experts suggest that because of the long lifecycle of turtles it may take 25 to 30 years to see much increase in the numbers. At the very least, however, we can hope that the steps taken to preserve their habitat and protect their breeding area will preserve the Green and Hawkeye Turtles which nest here from extinction.

In 1993 the Sangalaki Dive Resort was opened by a Malaysian Diving company, who also purchased the egg collection rights and the turtle population flourished despite depredations from armed looters. Unfortunately, the following year the concession was returned to commercial interests and the Green Turtle population went into serious decline. The original owners sold it in the late 1990s and there was subsequent friction with the Turtle Foundation and other Conservation groups about the impact of visitors on the Turtle population. In 2009, the newly refurbished resort was closed by the local administration in response to reports about the impact of their lights and habitation on the Turtle nestling, although the owners vigorously denied accusations of carelessness in these matters.

Because of the increased logging activities around the East Kalimantan, constant effort is needed to keep the beaches clear of driftwood, vegetation, and other debris which inhibits the newly hatched turtles on their escape to the sea and also discourages adult turtle from preparing their nests and laying their eggs on the beaches. Much work is needed to effectively protect the turtles and maintain their habitat.

Between dives it is worth taking the time to walk around the island, keeping your eyes open for the colourful birds large monitor lizards which may be hiding in the jungle, or sunning themselves on the rocks. You may even see the vulnerable turtle hatchlings making their precarious way down the beach, and through the shallow waters, to the ledges and gullies in the reef where they can hide and grow.

The reef around the island is also famous for its large population of Manta rays (known locally as "ghostfish" and apparently feared by fishermen) which can be seen all year round in great numbers. These impressive, plankton-eating giants are quite harmless and very interested in humans. While diving in the shallow waters of the reef, it is not unusual to see their shadows overhead. In addition to the Manta rays and giant turtles, there are many other colourful fish of all sizes, and corals.


Dive Resorts