If you are an experienced and adventurous diver, who wants to go off the beaten track, don't miss the opportunity to enjoy the unparalleled novelty of diving off Kakaban Island and snorkelling in its Lake. Boats dock at the pier on the south side of the island, and the amazing prehistoric lake is only a short walk on wooden paths through the gloomy, silent, mangrove swamps, escorted by the calls of birds, and insects. Most of the nearby resorts arrange day trips by speedboat, or you can negotiate with villagers and arrange a sail boat to take you there.
The marine riches of this fantastic site are largely unexplored and you may even discover new species during your visit and be the first to document their existence.
Biological Treasure Trove
Pristine Kakaban Island (Pulau Kakaban), designated a World Heritage Site because of its unique geology and abundant marine species, is part of the Derawan Archipelago. Its name is derived from the way in which the island embraces the lake and protects it from the sea.
Visiting this large, uninhabited island is truly an extraordinary experience, like stepping into a prehistoric world. Millennia ago, during the Holocene Age, a sudden upheaval of the sea bed formed a land-locked lake of sea water. Over time, the lake's salinity has been diluted by rain water, and the trapped marine life has adapted to the brackish water and simple food chain, creating a unique ecosystem which is a treasure trove of marine creatures.
Canadian marine biologist, Dr. Thomas Tomascik has called this place a biological paradise because of the abundance of unidentified species both in the mysterious lake, and on the surrounding reefs. Even the depth of the lake is unknown. Visitors can hope to discover new species even while they enjoy viewing the rare treasures which have already been found here.
Lake Kakaban is one of only three places in the world where you can find stingless jellyfish. It is home to four species: Aurelia aurita (moon jellyfish), Mastigias papua (spotted jellyfish), Tripedalia cystophora (box jellyfish), and the extraordinary Cassiopea ornata (upside-down jellyfish). Protected from natural predators in this isolated lake these have all lost their ability to sting and swimmers can safely enjoy the amazing experience of sharing the water with them and feeling their pulsating bodies around you.
In addition to the jellyfish, you can also see some notable fish species including serinding, coral fry and needlefish, and some rare algae and white anemone. Other simple forms of marine life which abound include sea snakes, cardinalfish, gobies, sea cucumbers, and soft-shelled crustaceans.
Walking inland the coral reefs, and shallow waters full of brightly coloured fish, gradually give way to dense jungle and mangrove forests and the silence is broken by the calls of tropical birds and the hum of insects.
Wooden paths, and piers (one on the lake, the other by the sea) allow tourists to access the lake, lagoon, and reef without disrupting the unique ecosystem of the island, which is jealously protected by the Indonesian government.
The surrounding reefs are also home to a rich variety of colourful corals and sponges, nudibranch, octopus, seahorses and eels, as well as several types of shark, manta rays, jack, tuna, snapper and barracuda. Expect to be overwhelmed by both the large size and the variety of fish you encounter.
Notable Dive Sites
The most commonly visited dive site on Kakaban is the wall at the Southwest point of the island. The strong, variable, upward and downward currents make diving challenging but they also bring a large variety of fish in impressive shoals. You can expect to see large specimens of barracuda, jacks, grey reef and variegated sharks, snapper, surgeonfish and trevally. The corals are also spectacular along the wall and include the amazing Gorgonian Sea Fans, as well as a variety of soft corals and sponges. A grab line has been permanently attached to help divers ascend to the shallows.
The drop-off point is also a wonderful dive. The wall drops down to 250m, and abounds in colourful fish, seahorses, and corals.
To protect the rare, stingless jellyfish in Kakaban Lake from being harmed by rising bubbles, diving is only allowed with special government permission. However, don't miss the opportunity to snorkel in the unplumbed depths of this warm, brackish, slightly cloudy lake.
A short walk through the mangrove forest will bring you to the lake and you can experience peculiar sensation of swimming among the luminous, pulsating jellied bodies of the four varieties of jellyfish identified so far. These include an upside species of Cassiopeia. The lake is also home to many other unique forms of marine life, from algae and the white sea anemones which prey on the jellyfish to a wide variety of sea snakes, cardinalfish, gobies, tunicates, sea cucumbers, tube worms, and colourful soft-shelled crustaceans.
As the daylight fades, the fish and corals glow with increasing strength adding to the eerie weirdness of the pristine lake. Even if you do not usually snorkel, this is a unique opportunity, but don't forget your water shoes, as the rocks can be sharp.
Best Time to Visit
Kakaban Island is open to diving all year round. However, for the best visibility visit during the dry season from March through October.