By Walter Mosley
I had fun snorkeling in the Derawan Islands Indonesia in the spring of 2026. I stayed at the Sienna Resort on Maratua Atoll. The Derawan Archipelago is in East Kalimantan off the coast of the island of Borneo. This was the second part of a two month solo snorkeling tour in Indonesia. I will be sharing five more reports from different areas visited on this trip. I will rate the reefs, visibility, marine life density, and boat logistics to help fellow snorkelers plan remote itineraries.
My Report About Snorkeling in the Derawan Islands
The Snorkeling Setup at Sienna Resort in Maratua Atoll
I spent five mornings snorkeling from a private speedboat with a captain and a snorkel guide. Most days began at 8:30 AM and we were back to the resort no later than 2:00 PM.
Reef Health and Terrain
Overall, the reefs in and around Maratua were in excellent condition, offering clear visibility with some lively currents for excellent drift snorkeling. The diversity of this area was top-notch, providing the highest level of marine megafauna and raw underwater adrenaline of my entire two-month journey.
Where I Went and What I Saw Snorkeling in the Derawan Islands
Sangalaki Island
On Sangalaki Island I toured a dedicated local green sea turtle conservation and hatchery, which is one of the largest in Southeast Asia. This is also a major hotspot for manta rays gliding gracefully in relatively shallow water between 10 and 20 meters deep.
Kakaban Island
I visited Kakaban Island’s famous landlocked marine lake, and swam around surrounded by millions of harmless, stingless, upside-down jellyfish. You have to hike through a dense jungle ridge about a quarter-mile before arriving at the hidden lake. Thank goodness the swimming ban had been lifted when I visited, so it was well worth the hike to snorkel.
Big Fish Country / The Channel
What a truly jaw-dropping, world-class experience snorkeling the spot known as Big Fish Country or The Channel. It is the large channel in the north part of Maratua Atoll. I got to snorkel directly through a massive, swirling “barracuda tornado” just off the coast. The school consisted of thousands of large barracudas—each measuring roughly 3-4 feet long—creating an unforgettable spectacle.
The Turtle Traffic
I explored a dedicated stretch of reef off the main Maratua Island that was heavily populated by exceptionally large, relaxed green sea turtles. This is a shallow, sandy bay.
Macro Excursions
I took a number of excursions to places where the focus was small creatures. Some of these sites included Fusilier Paradise, Gorgonzola, and Coral, which served as spectacular macro-snorkeling sites boasting highly unusual, well-camouflaged scorpionfish.
Bucket-List Day Trip
I swam alongside multiple gentle giant whale sharks at a fishing platform (bagan) off the coast of Talisayan. This was the highlight of my entire trip—snorkeling alongside two massive whale sharks (30 and 50 feet) just a meter away. Scary yet exhilarating!
Travel Logistics
I flew from Denpasar to Berau (BEJ) through Balikpapan. I purchased my Indonesian flights on Traveloka, which has a decent user interface, but ALWAYS verify flight status directly with the individual airline before travel dates. Frequent cancellations and schedule changes make air travel here a true challenge.
I spent a night at Mercure Berau and was picked up in the morning by a driver from Sienna Resort. After a short drive, we arrived at the pier at Sanggam. Two other guests joined me on a two-hour covered riverboat ride from the mainland, followed by an additional two hours of a rough, stormy open-sea crossing.
We were met by the resort van at the Dermaga Pier for a 20-minute drive to the other side of the atoll to take a short boat ride to the Sienna private island.
Another possible option is a once-a-week flight from Berau on the mainland directly to Maratua, but you’ll have to research this schedule.
More Posts From My Trip
First stop: West Bali National Park
Third stop: Gorontalo – Saronde Island