Aldabra Atoll tide times

Aldabra Atoll is the world's largest raised coral atoll, a UNESCO World Heritage Site, and one of the least-visited significant wildlife locations on the planet. It lies approximately 1,100 kilometres southwest of Mahé in the western Indian Ocean, closer to Madagascar and the East African coast than to the Seychelles granite islands. Access is restricted to scientific research permit holders and occasional transiting yachts; there is no commercial tourism.

The island is managed by the Seychelles Islands Foundation (SIF), which maintains a small research station. The tidal regime at Aldabra is among the most dramatic of any atoll in the Indian Ocean. 5 metres, and the atoll's geometry amplifies the effect: four passes (Passe Houareau, Passe Gionnet, Passe du Sud, and Passe Femme) connect the 155-square-kilometre lagoon to the open ocean.

At spring tides, water moving through these passes reaches 4 to 5 knots — among the strongest tidal currents in the tropical Indian Ocean. The passes are the ecological engine of the atoll: high nutrient, oxygen-rich oceanic water is pumped through the lagoon twice daily, sustaining a marine ecosystem that functions at a scale uncommon elsewhere in the Indian Ocean. The atoll is most widely known for its giant tortoises.

Aldabra holds approximately 100,000 Aldabra giant tortoises (Aldabrachelys gigantea), the largest population on earth — more than ten times the Galápagos population. The tortoises range across the main land rim, the beaches, and the scrub interior, and their grazing maintains the vegetation structure of the atoll in a way that no other large herbivore on the Indian Ocean islands does. They are diurnal and most active in early morning and late afternoon, retreating into shade during the midday heat.

The seabird colonies at Aldabra are among the most significant in the Indian Ocean. The atoll holds the world's largest frigatebird colony — both great frigatebird (Fregata minor) and lesser frigatebird (Fregata ariel) nest here in the tens of thousands. Red-footed booby (Sula sula) nests in the pisonia trees on the rim.

A flamingo colony occupies the shallow lagoon, and the endemic Aldabra rail (Dryolimnas cuvieri aldabranus) is the last flightless bird in the Indian Ocean basin. The marine environment of the lagoon and the outer reef is intact to a degree rare anywhere in the Indian Ocean. Hawksbill and green turtles nest on the beaches; dugong are present in the seagrass beds of the lagoon.

Manta rays use the passes on the tidal current, positioning themselves in the current stream to filter-feed. The outer reef wall descends steeply — 30 to 100 metres within a short horizontal distance — and supports the full complement of Indian Ocean large reef species including grouper, Napoleon wrasse, and shark species that have been fished out of almost every accessible reef in the region. Visiting Aldabra requires a research or educational purpose and an application to the Seychelles Islands Foundation at minimum six months in advance.

Transiting yacht crew can apply for a short stop permit. All other access, including private charter, is not available. This is a tide page, not a tourism advertisement — the tidal data here is provided for legitimate navigational and scientific planning purposes.

Predictions on this page come from Open-Meteo Marine, a gridded global ocean model. 3 metres on height — model-derived, not from a local gauge. The national authority is the Seychelles Fishing Authority (SFA) and the Seychelles Maritime Safety Administration (SMSA).