10 – 20 min
Emergence
She hauls out of the surf and crawls above the high-tide line.
Activities · Green turtles
Green turtle nesting in Derawan: where and when
Females come ashore after dark on Sangalaki and Derawan Island in every month of the year. The best season for the crossings is April to November, though trips run in every month.
- Nesting months
- All year
- Eggs per clutch
- ~100
- Days of incubation
- 45 – 70
- Best season
- Apr – Nov
When to go
Turtles nest all year; the sea sets the dates
Each female nests several times in one season, then skips two to four years, but the population is large and out of step, so some female comes ashore on almost any night. The limit is the crossing: April to November is the best season, and from roughly December to March, the wetter period, the open-water legs in the Sulawesi Sea can get rough.
Nesting happens after dark, typically between late evening and the small hours. Species: green sea turtle (Chelonia mydas), endangered on the IUCN Red List and protected under Indonesian law.
Best time to visit- Jan Rough Reduced
- Feb Rough Reduced
- Mar Variable Mixed
- Apr Calm 20 m+
- May Calm 20 m+
- Jun Calm 20 m+
- Jul Calm 20 m+
- Aug Calm 20 m+
- Sep Calm 20 m+
- Oct Calm 20 m+
- Nov Variable 20 m+
- Dec Rough Reduced
In season Crossings weather-dependent Sea state · visibility
Where they nest
Two nesting islands, and one for turtles underwater
Sangalaki is the principal nesting beach. Derawan Island is the other, and the one you most likely sleep on. Maratua matters underwater rather than on the sand.
| Location | Role for green turtles | Access | What you realistically see |
|---|---|---|---|
| Sangalaki | Principal nesting beach; no village or resort | About 45 min by speedboat from Derawan | Turtles in the water by day; nesting tracks on the sand |
| Derawan Island | Nesting beach and main accommodation base | About 40 min by speedboat from Tanjung Batu | Turtles grazing under the jetties; nesting after dark |
| Maratua | Feeding and resting habitat on the atoll rim | Speedboat from Derawan on day 2 | Turtles on almost every dive, including Turtle Traffic |
| Kakaban | Surrounding reef, not a nesting focus | Under 30 min by speedboat from Sangalaki | Turtles on the outer reef; the lake holds jellyfish |
Close to nesting sand at night? Base yourself on Derawan Island. Turtles underwater in numbers? Choose a Maratua stay. From Kalimarau (BEJ) it is about 2.5 – 3 hours by road to Tanjung Batu.
A nesting night
What a nesting night actually looks like
Slow, quiet and largely predictable: one to two hours from leaving the water to returning. Guides move visitors in only once she is committed.
Hatchlings
Hatchlings emerge 45 to 70 days after laying
A nest laid the night you watch hatches long after you fly home, but because nesting is continuous, nests laid weeks earlier hatch while you are there, at night or at first light.
Hatchlings, about five centimetres long, surface together once the sand cools and run for the brightest horizon: on an undisturbed beach, the sea. Torches, phone screens and unshielded lights pull them inland.
Sand temperature sets their sex, with warmer nests producing more females (the pivot is around 29°C). The commonly cited estimate is that one hatchling in a thousand reaches breeding age.
In the water
Seeing turtles in the water is far easier
Nesting is a night event and never guaranteed. In-water encounters are close to a daily certainty.
Where to meet them by day
Derawan house reef
Any snorkelling session normally puts you within a few metres of a turtle.
Maratua wall and Turtle Traffic
Turtles rest under overhangs and appear in numbers on the dive named after them.
Sangalaki
The manta feeding grounds sit off the same island as the main nesting beach.
Derawan Island
Under the jetties
Adult green turtles graze seagrass and algae, which is why they feed under the Derawan jetties in water shallow enough to watch from the pier without getting wet.
Beach rules
The rules on a green turtle nesting beach
Green turtles are protected in Indonesia. We do not run a hatchery; we keep encounters in the water by day and beach conduct tight at night.
On the beach at night
- No white light: no torches, phone screens or flash; guides use dim red light only
- Approach from behind the female and stay low
- Nobody moves close until she is laying
- No digging, no sitting on nest mounds, no fires or vehicles
Always
- No touching, riding or handling turtles at any age
- Do not move hatchlings: the crawl is how they orient
- Take your rubbish out
- Refuse turtle products of any kind
Trip costs
What a trip built around turtles costs
The 3D2N is the shortest trip that works: day 2 covers Maratua, Kakaban and Sangalaki. The 4D3N adds Talisayan whale sharks, Manimbora and Labuan Cermin. Rates nett.
Private trips include the car BEJ ↔ Tanjung Batu, private speedboat, stay, meals, snorkel kit, documentation, travel insurance and entrance fees. Not included: flights, fins, tips, personal expenses.
Answers
Green turtle questions
Green turtles nest in the Derawan Archipelago all year. The best season is April to November, when crossings are calmest. December to March is the wetter period: trips still run, but a crossing can be lost to swell, even though the turtles still come ashore.
Keep exploring
More in Activities
Plan your turtle trip
Tell us whether nesting or snorkelling comes first
Send your dates and group size, and we tell you where the trip puts you among turtles: in the water by day and at the conservation site on Sangalaki.