Derawan Islands: Reefs, Turtles and Jellyfish Lake
Berau Islands: what the Derawan archipelago is like
The Derawan Islands are a scattering of around thirty islands in the Sulawesi Sea, belonging to Berau Regency in East Kalimantan. Alongside the many small sandbanks, reefs and atolls, four islands draw most visitors: Derawan, Maratua, Sangalaki and Kakaban. Each one has its own character, so the choice of where to stay matters as much as the choice of activities.
The archipelago suits a trip built around the water. Snorkelling and diving over reefs, boat journeys between islands, turtles on the beaches and in the shallows, and the enclosed lake on Kakaban are the main draws. Most people reach the islands through Tanjung Redeb, the town on the mainland, followed by a speedboat crossing of a few hours. Sea conditions decide how smoothly that crossing goes, so build some slack into the first and last days of the trip.
How the four main islands differ
Derawan is an inhabited island with a village at its heart and a long history as a fishing community. Fishing remains a major source of income for the islanders, and the boats moored along the shore show how closely village life depends on the sea. Staying in or near the village makes Derawan the most practical base for a first visit, with boat trips arranged out from it.
Maratua is one of the two inhabited islands in the group and has four villages: Bohe Silian, Payung-Payung, Teluk Alulu and Teluk Harapan. The island is large enough that getting from a room to a village, a jetty or a departure point can take a little planning. It also has its own airport, but flights there are limited, so most travellers still arrive by sea. Maratua is the island to choose if you want wide coastal scenery and a choice of dive and snorkel spots.
Sangalaki is known for turtles and manta rays. It is a conservation area where turtles nest, their eggs hatch and hatchlings are released, and it is one of the places in the group where turtles are commonly seen in the water. Manta rays are also recorded in the waters of the Derawan group, and Sangalaki is one of the islands associated with them. Neither animal can be booked like a show. A manta may be absent on a day when the water looks ideal, and turtle activity changes with the season and the weather.
Kakaban is memorable for the lake inside the island, which is separated from the open sea and holds stingless jellyfish. Reaching the lake involves a walk from the landing area, and the experience of standing above the water, looking down at the jellyfish, is quite different from anything on the surrounding reef. Local arrangements for the lake can change, so ask the boat crew and any guide what is allowed on the day before entering the water. If swimming is not permitted, the walk through the island and the contrast between the lake and the sea still make the stop worthwhile.
Reefs, seagrass and wildlife are connected
The archipelago is not simply a line of beaches with a few snorkelling spots. Reefs, reef slopes, shallow flats and seagrass meadows form one connected marine landscape. Seagrass is important feeding ground for green turtles, and the reefs shelter the reef fish and invertebrates that visitors come to see. That is why the water between islands is part of the experience rather than empty space between attractions. Look below the surface when the boat is stopped and the crew says it is safe.
The wider area lies within the Coral Triangle, one of the richest marine regions in the world, and its reefs are among the most biodiverse in Indonesia. Those figures describe the region as a whole. What a visitor sees on one outing depends on the site, the tide, the currents and the weather. A calm surface does not guarantee clear water underneath, and a cloudy morning does not mean there is nothing worth seeing. If one kind of encounter matters most to you, ask the operator which sites suit that goal on your dates.
Turtles are part of the wildlife that makes the archipelago special. Green turtles and hawksbill turtles are both recorded here, and they are seen on the reef and near the beaches. Green turtles are the species most often associated with the nesting beaches. Turtles in the water need room: keep a steady distance, do not chase one for a photograph and do not swim between an animal and the surface. Turtles on the beach need even more space, so keep well back from any nest.
Manta rays are a major attraction in the group, and the reef slopes at several sites are known for them. Their movements follow the current and the plankton, so a sighting is never guaranteed. Snorkellers should enter the water only when the crew says it is safe, keep their fins away from other swimmers and let a manta choose its own path. Divers should not block an animal’s route or crowd it. These simple choices protect the animal and usually make the encounter better for everyone.
Choosing a base and shaping island days
Choose Derawan when you want a settled island base, easy access to the village and boat trips arranged around it. Choose Maratua when the island itself is part of the appeal and you are happy to plan around where you sleep and how you travel between villages. Add Sangalaki as a wildlife-focused day when the sea and the local arrangements allow it. Kakaban works best as a deliberate stop rather than a rushed add-on, because the landing, the walk, the lake and the return boat all take time.
A multi-day plan should group nearby stops rather than crossing back and forth. One day can focus on the reef and village surroundings of Derawan. Another can be set aside for Kakaban and Sangalaki if the sea is calm. A separate block on Maratua gives time to see its villages and coastline. The order depends on the boat, the departure point, the tide and the conditions on each morning. Keep at least one flexible day for the trip, so that a cancelled crossing does not wipe out the outing you cared about most.
Snorkelling and diving need different pacing. A snorkelling day often means repeated short entries from the boat with waiting between sites, while a dive itinerary depends on the briefing, the equipment, the surface intervals and each diver’s experience. Do not book more water activity than you can manage after a long transfer. If one person in a group does not dive, check whether the planned route includes shallow-water or shore time for them, because a boat day built around dive sites can leave a non-diver waiting aboard for long stretches.
For a first visit, decide which experience would make the journey worthwhile: a few relaxed days on one island, particular reef sites, a chance to snorkel over turtle-rich water, or the unusual lake on Kakaban. Build the trip around that choice. Trying to collect every island in a short stay turns a marine trip into a long sequence of boarding and disembarking, and the islands reward time spent with one reef or one shoreline.
Getting to the islands from Berau
Most itineraries begin in Tanjung Redeb, the mainland town of Berau. From there, a speedboat takes visitors out to the islands, and the crossing from the mainland pier to Maratua is typically a few hours, depending on the boat and the sea. Shorter crossings start from Tanjung Batu. Before choosing a return flight, establish where the boat leaves, how the transfer to the pier is arranged and what happens if the sea is too rough to cross.
Flights are the other route in, but schedules are limited and small regional services can change. Maratua’s airport is served by a small number of flights, and the timetable may not match an onward boat or an international connection. Treat air access as one option to check carefully, not as a guarantee. Leave a buffer night on the mainland or an extra day on the islands if you are arriving from far away, so that one disrupted leg does not break the rest of the plan.
Crossing times vary with destination, vessel, route and sea state. A fast boat on a calm day and a slower or indirect transfer are not the same planning assumption. Ask the operator for the intended route and the realistic sequence from your hotel to your island, rather than relying on a single generic duration. Confirm whether the boat lands at the island where you will sleep or whether another transfer is needed. That detail matters when combining Derawan and Maratua, which are separate stops rather than neighbouring parts of one resort.
Weather can disrupt the sea leg, and a cancelled crossing is a safety decision, not a service failure to be overcome by pressing for departure. Keep fixed commitments such as onward flights away from the day you expect to return to the mainland. If your route starts far away, connections through East Kalimantan take time. A buffer night in Berau is usually more useful than a tight chain of separate tickets.
Weather, water and practical expectations
The sea is warm all year, but comfort on a boat depends more on sun, wind, spray and motion than on air temperature alone. Carry drinking water, sun cover and a dry bag for anything that cannot get wet. Reef trips can mean strong sun with little shade between stops, so a hat and a light long-sleeved shirt for the water are useful. If you are prone to seasickness, take precautions before boarding rather than waiting until the boat is moving.
Seasonal patterns influence rain, sea state and underwater visibility, but they do not create a guaranteed window for every activity. The more useful question is not only which month is best but how much flexibility you have if a crossing or a planned site is not possible. Divers should ask about currents and whether a site suits their experience. Snorkellers should be honest about their swimming ability. A flotation aid can make a boat outing far more comfortable for anyone who is not confident in open water.
On shore, village paths and jetties are working parts of small communities. Ask before photographing people or entering private areas, keep noise low around homes and take rubbish back with you. Local people live beside the same water and use it for transport and work, so treat the village as someone’s home rather than a backdrop. Avoid standing on coral, collecting shells or feeding fish. At Kakaban, do not lift or handle the jellyfish, and do not enter the lake with equipment unless the local rules allow it.
How the Derawan Islands fit a longer Kalimantan trip
The islands pair naturally with a mainland journey through Berau, but they do not sit on a simple overland loop. Tanjung Redeb is a useful place to manage arrivals and departures, although it is not a substitute for time on the water. Other stops in East Kalimantan can be added if flights and your interests support them. Keep those choices secondary when the main reason for travelling is the archipelago, since each extra region adds connections and takes days away from the islands.
Visitors arriving from Bali should think in blocks: reach East Kalimantan, reach Berau, cross to the islands and return with margin. The route is more satisfying when the crossings do not consume the holiday’s most useful days. If diving is the priority, allow enough nights to rest between travel and water days. If Kakaban is the priority, avoid placing it on the final day before a flight. If wildlife is the draw, plan for uncertainty rather than promising a sighting to everyone in the group.
For more detail on each stop, read about Maratua Island, diving in the Derawan Islands, Pulau Sangalaki and the Kakaban lake. Use them to choose a base and understand what each outing involves. The sea still decides what can happen on a particular day.
Questions travellers ask about the Derawan Islands
How many days should I allow?
Allow several days on the islands if you want to visit more than one of Derawan, Maratua, Kakaban and Sangalaki. The crossing from the mainland and the possibility of weather disruption make a very short stay vulnerable to losing its main outing. Divers may want extra days for a less compressed schedule.
Can I swim in the lake on Kakaban?
That depends on the local arrangements on the day you visit. Ask the boat crew or guide before entering the water, follow their instructions and never touch or lift the jellyfish.
Will I see manta rays or turtles?
No wildlife sighting is guaranteed. Manta rays move with the current, and turtles appear where and when conditions allow. A responsible visit gives animals room and treats the habitat as the point of the trip, even when a close encounter does not happen.
Is it possible to visit from Bali in a short break?
It is possible, but the mainland journey and the sea crossing make this a demanding choice for a brief break. Flights, road travel and boats need to connect, and weather can change the sea leg. A longer trip with a mainland buffer suits the distance better.