The Coral
Triangle

Drop below the surface almost anywhere between Bali and the Solomon Islands and you enter the richest marine region on the planet. The Coral Triangle covers about six million square kilometres of sea around Indonesia, Malaysia (Sabah), the Philippines, Timor-Leste, Papua New Guinea and the Solomon Islands. It holds 76 percent of the world's known coral species and 37 percent of its coral reef fishes, and six of the seven marine turtle species live here. More than 100 million people depend on its reefs, mangroves and fisheries.

This is a book for the curious traveller who wants to understand what they are looking at, as well as where to go. It starts with how the Triangle works: the Indonesian Throughflow that carries Pacific water through Indonesia's straits, where the reefs are, how a reef is built, and why this one corner of the ocean holds so much life.

It then takes you country by country, with dive regions, seasons, airports and protected areas for each of the six nations, and a chapter on the sea peoples whose lives are tied to these waters.

It is also frank about the pressure the reefs are under. Between January 2023 and April 2025, bleaching-level heat stress reached about 84 percent of the world's reef area, and the Triangle was not spared. The book shows where heat, murky water, oil and fishing hit hardest, and where protected areas are fighting back.

The maps are the heart of it. Nine full-page plates, each built from public scientific data, show the boundary, the currents, the reefs, coastal habitats, water clarity, heat stress, oil slicks, marine parks and Indonesia's best dive regions. The last part helps you plan: a year on the reef, trip planning, encounter codes, snorkelling and freediving, and how you can help.