Indonesia lies at the very centre of the Coral Triangle, the richest marine region on the planet. Its warm seas hold more species of coral and reef fish than anywhere else on Earth, and its scattered islands offer everything from world-class scuba diving to lazy snorkelling above turtle-filled shallows. Whether you are a certified diver chasing manta rays or a beach lover with a mask and fins, Indonesia's underwater world is unforgettable. This guide maps out the finest islands and dive destinations across the archipelago.
Raja Ampat, the crown jewel
Off the coast of West Papua, Raja Ampat is widely considered the epicentre of marine biodiversity on Earth. Scientists have recorded around three quarters of all known coral species here, alongside more than a thousand kinds of reef fish. The name means Four Kings, after the four main islands, but the archipelago is made up of hundreds of jungle-topped karst islets rising from turquoise water.
Above the surface, the viewpoints of Wayag and Piaynemo reveal labyrinths of pointed limestone islands scattered across the sea, one of the most photographed scenes in all of Indonesia. Below the surface, divers drift over gardens of soft coral pulsing with life, past reef sharks, wobbegongs and huge schools of fish. Raja Ampat is remote and requires effort to reach, which has helped keep its reefs among the healthiest in the world.
Bunaken, Wakatobi and the reefs of Sulawesi
The island of Sulawesi is ringed by superb diving. Bunaken, a marine park near Manado in the north, is famous for its dramatic coral walls that plunge into the deep blue, alive with turtles, barracuda and clouds of reef fish. Further southeast, Wakatobi is a byword for pristine reefs and outstanding visibility, a place beloved by serious divers who want healthy coral far from the crowds.
Komodo, Nusa Penida and the mantas
Komodo National Park is famous for its giant lizards, but beneath the waves it is one of the best places in Indonesia to swim with manta rays. Strong currents feed a spectacular ecosystem, and sites like Manta Point draw these gentle giants to feed and glide. Closer to Bali, the island of Nusa Penida offers two of the ocean's most sought-after encounters: manta rays that cruise its cleaning stations year round, and the strange, disc-shaped mola mola, or oceanic sunfish, that rises from the depths in the cooler months.
The Gili Islands and Derawan
For those who prefer a gentler pace, the three Gili Islands off Lombok, Trawangan, Meno and Air, are car-free specks of white sand and clear water. Snorkellers here regularly meet green sea turtles gliding over the reef just off the beach, making the Gilis one of the easiest places in Indonesia to swim beside these graceful animals. Far to the north, off East Kalimantan, the Derawan archipelago offers turtles, reef sharks and a lake famous for its harmless stingless jellyfish.
Seasons, snorkelling and protecting the reefs
- The dry season, roughly April to November, generally brings the calmest seas and best visibility, though each region has its own rhythm.
- Snorkelling suits beginners and needs only a mask, snorkel and fins; scuba diving opens up walls, currents and deeper reefs but requires certification.
- Never touch or stand on coral, which is a living animal that takes decades to grow.
- Keep a respectful distance from turtles, mantas and sharks, and never chase or ride them.
- Choose reef-safe sunscreen and dive operators who follow marine park rules.
An underwater country
With more than seventeen thousand islands, Indonesia is as much a nation of the sea as of the land. From the untouched reefs of Raja Ampat to the friendly turtles of the Gilis, its waters offer a lifetime of discovery, and every careful visitor helps keep this fragile paradise alive for the future.