Coral built most of what visitors come to French Polynesia to see: the lagoons, the white-sand motu, the passes full of fish and, in the Tuamotus, the atolls themselves. Understanding how these reefs work makes snorkeling more interesting and makes it obvious why a fin kick in the wrong place matters.
Two kinds of reef landscape
The Society Islands are high volcanic islands ringed by reef. Close to shore there is often a fringing reef; further out a barrier reef encloses a lagoon, broken by passes where water flows in and out with the tide. In the Tuamotus, the volcano has subsided out of sight and only the ring of reef remains, forming an atoll around a lagoon. Rangiroa has the largest lagoon in French Polynesia and Fakarava the second, and Fakarava’s Garuae pass, about 1,600 metres wide, is the widest in the territory, according to Tahiti Tourisme’s Fakarava diving guide. Fakarava is also part of a UNESCO biosphere reserve that includes neighbouring atolls.
What lives where
| Reef zone | What you see | Who it suits |
|---|---|---|
| Shore and fringing reef | Small coral heads, juvenile fish, sea cucumbers | Beginners and children with supervision |
| Lagoon coral gardens and motu channels | Dense coral, butterflyfish, parrotfish, clownfish | Confident swimmers; some channels drift with the current |
| Passes | Sharks, rays, schools of fish on the tide | Experienced swimmers or divers with a guide |
| Outer reef slope | Hard coral walls and open-ocean species | Divers |
A reef that has been studied for decades
Moorea is one of the best-studied coral reefs in the world. The French research centre CRIOBE runs a station on the island, and international teams work alongside it. Their records show how resilient, and how exposed, these reefs are. A peer-reviewed study of Moorea’s north shore found that an outbreak of coral-eating crown-of-thorns starfish and a cyclone reduced coral cover on the outer reef to under 3% by 2010, followed by a rapid recovery through new coral settling and growing over the next seven years.
That recovery is encouraging, but reefs everywhere are under pressure from warmer seas, which cause bleaching, and from local pollution and physical damage. Visitors cannot fix ocean temperatures, but they can avoid adding stress to a reef that is already working hard. Several projects grow and replant coral in the lagoons; our coral restoration guide covers how to visit or support them.
Where to see healthy coral
Good reef snorkeling is spread across the islands. The Coral Garden off a motu at Taha’a is a gentle drift through coral heads. On Moorea, the channel between Motu Tiahura and Motu Fareone has a coral garden near the west-coast hotels. Huahine’s coral garden near Fare is excellent but can run with current. In the Tuamotus, Fakarava, Rangiroa and Tikehau offer clear water and pass snorkels when the tide is incoming. Our snorkeling islands guide compares them for different levels.
Reading a lagoon from the surface
Colour tells you what is below. Pale turquoise usually means sand, darker brown or olive patches are coral heads, and deep blue marks a channel or the drop-off at a pass. Kayakers and paddleboarders can use this to avoid grounding on coral at low tide, and snorkelers can plan a route that follows sand between coral heads instead of finning over the top of them. Wind against tide in a channel makes short, steep chop, a sign the current is running.
Choosing a reef-friendly operator
Good operators tie up to moorings or anchor in sand rather than on coral, keep groups small, give an in-water briefing and stay with their snorkelers. They will also tell you when a site is closed or when the current is too strong. Ask how they choose sites on the day, and choose the operator that answers with conditions, not with a promise.
Make the visit respectful
Float, don’t stand. If you need to rest, roll onto your back or hold a buoy or the boat line, never a coral head. Keep fins horizontal and away from the bottom, and secure cameras and loose straps so they don’t drag. Don’t feed fish, chase turtles or move anything to improve a photograph. Hard corals are protected under CITES, the international wildlife trade convention, so don’t buy coral souvenirs or take pieces home, even dead fragments from the beach.
A rash guard and leggings reduce the amount of sunscreen washing into the lagoon. Our snorkeling etiquette guide covers sunscreen choices and in-water conduct in more detail.
Common planning mistakes
Judging a reef’s condition from an old photograph, snorkeling a pass at the wrong tide, and wading through shallow coral in reef shoes because it seems faster than swimming around.
Staying safe on the reef
The Government of Canada advice recommends reef shoes against coral cuts and stonefish, and warns that tidal currents can be strong. Wear shoes for entering from shore over rubble, then swim once the water is deep enough. Clean any coral graze promptly, since small cuts can become infected in the heat. Snorkel with a buddy, stay out of marked boat channels, and wear a brightly coloured cap or tow a small buoy when swimming from shore, so boat drivers can see you.
Accessibility and individual needs
Children learn a lot at a shallow sandy edge with a guide; make sure they can float calmly in a vest so they do not stand on coral to rest. Snorkellers who tire easily can ask for a boat trip that anchors over sand next to a coral garden, so the boat is always close.
After booking
Ask whether any area is closed for protection or restoration, and whether the operator gives an in-water briefing on where coral starts.
On the day
When the water is rough or visibility is poor, a glass-bottom boat, a reef talk or a visit to a coral nursery still shows reef life without the pressure of crowded swimming.