Seychelles Outer Islands Passage: One-Way to Aldabra aboard MY Basilisk

Embark on MY Basilisk at 10:00 AM from Mahé. After a welcome and cruise briefing, you'll set course around midday for the Amirantes, beginning the expedition with the beautiful Desroches Island.

The Amirantes is a linear chain of coral islands and atolls lying west of the granitic Seychelles. Desroches, the largest and closest to Mahé, stretches 6 km long and 1.5 km wide, hidden beneath swaying coconut palms and lush endemic vegetation. The island is encircled by 14 km of pristine white sand beaches, kissed by crystal-clear turquoise waters.

The Alphonse Group comprises two neighboring atolls - Alphonse and St. François, the latter home to the islands of St. François and Bijoutier. Among the most stunning in the Seychelles, Alphonse is arrowhead shaped, with white surf trailing behind like a wake. Once a thriving coconut plantation producing 100,000 coconuts a month, the island is now peacefully abandoned, reclaimed by nature.

As we make our crossing from the Alphonse Group toward Aldabra, we’ll be on the lookout for marine mammals, including various species of whales and dolphins. In the evening, join us for a fascinating lecture on the natural history of the Seychelles.

A visit to Cosmoledo rivals that of Aldabra, yet in many ways, it surpasses it in sheer remoteness and isolation. Wild, untouched, and uninhabited, Cosmoledo remains one of the least visited corners of the Seychelles - and the world. We expect to arrive in the afternoon, with a visit to the abandoned settlement and a dive off West Island (Menai), where turtles are especially plentiful.

Home to bird species not found on Aldabra, including vast colonies with Seychelles’ largest populations of Red-footed Boobies, Masked Boobies, and Sooty Terns. A unique race of Madagascar White-eye is found only here. It is also the last breeding site in Seychelles for the Brown Booby, extinct elsewhere in the islands. Diving is excellent, with rich marine life and coral reefs that have survived more intact than almost anywhere else in the western Indian Ocean. The shallow lagoon near the main island is full of turtles, including hatchlings. A visit to the north island offers an incredible wall diving experience.

Often called the Crown Jewel of Seychelles, Aldabra is the world’s largest raised coral atoll and a UNESCO World Heritage Site. Covering 150 sq km, it has no permanent population aside from the research team on Picard Island.

Home to around 100,000 Giant Tortoises, Aldabra also shelters rare plants, birds, and one of the world’s key nesting grounds for endangered Green Turtles. Bird highlights include the flightless Aldabra Rail, Frigatebirds, and several endemics like the Aldabra Drongo and Fody.

We visit the research station and old settlement, cruise the West and Main Channels, and snorkel at sites like Passe Dubois and Anse Var. Snorkelling through the mangrove forests offers a unique opportunity to visit the home to a plethora of marine life. Recent Dugong sightings hint at a possible return of this elusive marine mammal to Seychelles waters.

Assumption Island is home to a stunning arc of coral sand and vibrant offshore waters, where you can explore colourful reefs teeming with snapper, butterflyfish, and angelfish. Though its seabird colonies were impacted by early 20th-century guano mining, the island’s vegetation is now gradually recovering.

Explore Astove Island, home to one of the world’s most spectacular snorkelling sites—its dramatic coral reef drops steeply just 250 metres from shore and teems with vibrant marine life, including Green Turtles, hundreds of fish species, and historic shipwreck anchors. After a short time at the island, you’ll disembark MY Basilisk for your return flight to Mahé.