Derawan: the islands off East Kalimantan

The Derawan islands sit off the coast of Berau in East Kalimantan, where the shelf drops away into the Sulawesi Sea. There are a few dozen islands in the group, but four matter to travellers: Derawan, with its village and turtle hatchery; Kakaban, with a landlocked lake full of stingless jellyfish; Sangalaki, a nesting beach for green turtles; and Maratua, a large atoll with walls and channels on its outer edge.

This is not the easiest place in Indonesia to reach, which is part of why it still feels like an outpost. You fly to Berau, drive for two or three hours, and take a boat. Once there, the routine is simple: sleep in a wooden room, eat fish, dive or snorkel in the morning, and watch the sun go down over a horizon with no land in it.

The islands and how they fit together

Derawan is the main inhabited island and the usual base, with a village of stilt houses, a handful of guesthouses and a small turtle hatchery. Kakaban lies a short boat ride north, a raised coral island with a saltwater lake in its centre. Sangalaki is further east, a flat, palm-covered island where green turtles come ashore to nest. Maratua is the largest, an atoll with a lagoon and a channel to the open sea.

The distances are short by boat, and most guesthouses run day trips that combine two or three islands. The sea is usually calm from March to October, which is also the best season for visibility. In the wet season the crossings can be rough and trips are cancelled, so build in some slack.

Kakaban and the jellyfish lake

Kakaban's lake is one of the strangest places in Indonesia. It is a landlocked body of brackish water, cut off from the sea thousands of years ago, where several species of jellyfish have evolved without stinging cells. You can swim among them, and they bump gently against your arms instead of burning you. The lake is also home to a distinctive white sponge and a forest of mangroves around its rim.

The walk from the beach to the lake takes about ten minutes on a boardwalk through the forest. Rules are strict: no sunscreen in the lake, no touching the jellyfish, no standing on the coral, and life jackets are required. The lake is fragile, and the number of visitors is controlled. Go early in the day, and treat it as a nature reserve rather than a swimming pool.

Turtles at Sangalaki and Derawan

Sangalaki is one of the most important green turtle nesting sites in Indonesia. Females come ashore at night to lay eggs, and the island's hatchery and rangers collect and rebury clutches to protect them from predators and poaching. Hatchlings are released in the late afternoon or evening, and watching a hundred small turtles scramble for the sea is the highlight of many visitors' trip.

Derawan also has a hatchery and a resident population of green turtles that graze on the seagrass beds around the island. You can snorkel with them, but keep your distance, do not touch them, and never block their route to the surface. The turtles are the reason the archipelago is protected, and the tourism economy depends on them staying.

Diving and snorkelling

The diving around Derawan and Maratua is excellent, with walls, channels, coral gardens and big pelagic fish. Maratua's outer reef drops steeply into deep water, and the channel on its western side is known for grey reef sharks, barracuda and occasional manta rays. The sites around Kakaban and Sangalaki are shallower and better for snorkellers, with hard coral, giant clams and reef fish.

Visibility is usually 20 to 30 metres in the dry season, and the water is warm. Currents can be strong at the channel and wall sites, so dive within your certification and go with a local operator who knows the tides. There is no hyperbaric chamber nearby, and the nearest hospital is in Berau, so dive conservatively.

Villages, food and where to stay

Derawan village is a small, friendly place of stilt houses, a mosque, a school and a few shops. The Bajau and Bugis communities have lived on these islands for generations, and fishing is still the main work. There are no ATMs on Derawan, and electricity can be intermittent, so bring cash and a power bank.

Accommodation ranges from simple fan rooms to a few dive resorts with air conditioning and generators. Food is mostly fish, rice and vegetables, with the catch of the day grilled or fried. Alcohol is limited and expensive, and the islands are conservative, so dress modestly away from the beach. Most packages include meals and boat trips.

Getting there and a plan

Fly to Berau's Kalimarau airport, then drive about two to three hours north to Tanjung Batu, where speedboats leave for the islands. The boat to Derawan takes 30 to 45 minutes; Maratua is another 30 to 60 minutes beyond that. Some resorts arrange the whole transfer, which is the simplest option.

Four days is the minimum to see Derawan, Kakaban and Sangalaki without rushing. Five or six days lets you add Maratua and several dives. The best season is March to October, with the calmest seas and clearest water; July and August are the busiest. Bring reef-safe sunscreen, a rash guard and cash.

• Day 1: fly to Berau, transfer to Tanjung Batu, boat to Derawan, sunset on the jetty.
• Day 2: Kakaban jellyfish lake in the morning, Sangalaki turtles in the afternoon.
• Day 3: diving or snorkelling at Maratua's walls and channel.
• Day 4: Derawan village, turtle hatchery, and the boat back to Berau.

Questions people actually ask

How do I get to the Derawan islands?

Fly to Berau, drive two to three hours to Tanjung Batu, then take a speedboat. Derawan is 30 to 45 minutes from the mainland, and Maratua is further. Most guesthouses and resorts arrange the full transfer.

Can I swim with the jellyfish at Kakaban?

Yes, with a guide and a life jacket. The jellyfish are stingless, but you must not touch them or wear sunscreen in the lake. The visit is controlled to protect the ecosystem, and the boardwalk and lake can be closed at short notice.

When is the best time to dive in Derawan?

March to October, when the sea is calm and visibility is best. July and August are the busiest. The wet season brings rough crossings, cancelled boat trips and lower visibility.

Is there internet and electricity on Derawan?

Electricity is usually available but can be intermittent, and phone signal is patchy. There are no ATMs, so bring enough cash for your whole stay and a power bank for your devices.