Natural Selection

Day 1 · Yacht Isabela II

Into the islands at Baltra

The flight from the mainland lands on Baltra, a flat scrub island that was an American airbase in the 1940s and is now the archipelago's gateway. Park formalities and the transit-card check are done inside the terminal, and the crossing to the ship goes from there: nobody stays on Baltra, which has no town and nothing to see.

The highlands are the wet side of Santa Cruz, green and misty where the coast is dry, and giant tortoises climb up into them to graze on private farmland that has simply left them to it. The same slope is riddled with lava tunnels, one of them wide enough to walk through upright for several hundred yards.

Las Bachas is a soft white beach on the north coast of Santa Cruz, a wet landing straight off the panga into shallow water. Sea turtles nest in the dunes behind it and leave tractor-width tracks up the sand overnight, and a brackish lagoon a few steps inland holds flamingos and pintail ducks. The name is a corruption of "barges": two American landing craft were abandoned here after the war and the ribs of one are still on the beach.

Day 2 · Yacht Isabela II

Punta Pitt

A trail climbs a wind-carved ravine on the eastern tip of San Cristobal to the only ground in the islands where all three boobies nest together: blue-footed on the open trail, red-footed in the shrubs, Nazca along the cliff. Each keeps to its own layer, which is how three species that eat the same fish share one headland.

The breeding centre at Cerro Colorado sits in the green south of San Cristobal and raises the island's own race of giant tortoise. Hatchlings are held until their shells are hard enough to survive introduced rats, then released into the hills above, and the enclosures are laid out so the released ones wander back through on their own.

Day 3 · Yacht Isabela II

Gardner Bay

Gardner Bay is a mile of white coral sand with a sea lion colony spread the whole length of it and no shade, so the animals simply lie where they land and let people walk around them. The water is flat enough for kayaks and paddleboards, and the snorkeling is off the islet at the end of the beach, where the rock drops away and the fish stack up against it.

Espanola is the oldest island in the archipelago and the flattest, which is why the seabirds own it: no highland means no cover for anything that hunts them. The trail crosses marine iguanas flushed red and green in breeding colour to a blowhole throwing spray a hundred feet off the cliff edge, and from April through December the entire world population of waved albatross nests along this one headland and launches off that cliff to feed.

Day 4 · Yacht Isabela II

Punta Cormorant

The landing beach at Punta Cormorant is green, coloured by olivine crystals weathered out of the lava, and the trail behind it reaches a brackish lagoon where greater flamingos feed with their heads underwater. The beach on the far side is flour-fine white sand where sea turtles haul up to nest, and rays lie in the shallows off it in numbers.

Champion is a small cone off the northeast corner of Floreana with no landing on it: the visit is a panga circuit and a snorkel over the drop-off, where sea lions come out to meet swimmers. Fewer than two hundred Floreana mockingbirds are left alive and this islet holds most of them, the species having died out completely on the island it is named after.

A wooden barrel above the beach has been forwarding mail by hand since the 1790s, set up by whalers so homebound ships could carry letters south. The system still runs on the same rule and nothing else: you sort through what is in the barrel, take any postcard addressed near where you live, and deliver it yourself when you get home.

The visit runs in two parts: a panga through the mangrove channels of the north shore, past sea lions, turtles and golden rays in shallow water, then a wet landing and an easy climb to the lookout above. A self-declared baroness settled Floreana in the 1930s, announced herself its empress, and vanished along with one of the two men she had brought; she is said to have spent hours on this hill watching the sea for ships, which nobody has explained either.

Day 5 · Yacht Isabela II

Punta Moreno

The walk at Punta Moreno crosses a black lava delta that reaches the sea, cracked open in places into brackish pools held in the rock. Flamingos, pintail ducks and gallinules use them, which is an odd thing to meet in the middle of a lava field, and Cerro Azul stands behind the whole scene along the spine of Isabela.

Punta Mangle is a set of mangrove channels on the Fernandina coast worked by panga, quiet enough that the engine goes off. Penguins fish the shallows, flightless cormorants sit on the roots and golden rays cross the sand below the boat. The Bolivar Channel outside carries the richest feeding in the archipelago, and whales pass through it.

Day 6 · Yacht Isabela II

Eden Islet

Eden Islet is a tuff cone broken open on one side, and the visit stays on the water: a panga circuit under the walls where white-tipped reef sharks patrol the shallows and blue-footed boobies fold and dive around the boat. Golden rays cross the sand below in numbers.

North Seymour is flat, low and covered in the two birds people come for. Male magnificent frigatebirds inflate scarlet throat pouches the size of a football and hold them inflated for hours over the trail, while blue-footed boobies perform their courtship dance a few feet away, lifting each foot in turn because the colour is the point. Sea lions and land iguanas hold the ground between them.

Day 7

Ashore on Santa Cruz, and the flight home

Breakfast aboard, then the last disembarkation of the trip and the road north across Santa Cruz to the channel, the ferry over it and the short run to the airstrip on Baltra for the flight to the mainland.