Réunion · France · Cave & cavern · Reef · Pelagic & blue water
Les Trois Arches
Three arches left standing from a collapsed lava tunnel
Area photo: Cynomana · CC BY-SA 4.0
South of Saint-Pierre, an old lava tunnel has collapsed and left only its side walls and three arches standing, ten metres high and ten metres wide. The site runs from 40 to 60 m and the current over it is often strong, which is what brings the pelagics in and what restricts the dive to the most experienced divers on the boat.
Where it is and how deep
21.3722° S, 55.5569° EApproximate position — the dashed circle shows where the site lies; your operator's briefing has the mooring.
The dive
What you dive here is the wreckage of a lava tunnel. The roof of the cavity has gone and what remains are the side walls and three arches, each around ten metres high and ten metres wide, standing clear of the ground. The site is worked between 40 and 60 m, so the arches are seen deep and the time available to swim among them is measured in minutes rather than the length of a tank.
The current is the other half of the dive. It is often strong here, which is precisely why the site is dived: pelagics come in to hunt along the structure and the recommendation is to be in the water early in the morning to see it. Various species of coral fish live around the walls. Between the depth, the narcosis that comes with it and the water movement, this is not a site to try on an average level of experience.
Marine life and season
The sources we used don't single out particular species here.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Fair | Fair | Good | Good | Prime | Prime | Prime | Prime | Prime | Prime | Good | Fair |
Season follows Réunion: May–Oct is the dry season with the calmest water and humpbacks Jul–Oct; Jan–Mar is cyclone season.
Know before you go
- The current is often strong and the site runs to 60 m — a bad combination if the plan is loose. Operators reserve it for their most experienced divers.
- The directory pairs the depth with narcosis in describing this dive: at 40 to 60 m, fix the descent and the turn before you leave the boat.
Sources
- Les trois arches — Carte de La Réunion
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