Blue-footed boobies

The first leg of our journey took us from Baltra Island to its neighbour, Santa Cruz. We stopped at Dragon Hill, a jagged peak presiding ominously over the land inhabited by the iguanas after which it is named. Away from the beach the landscape gave way to miles of bushy scrubland. Yet, even in such an apparently uninhabitable environment, life had flourished. There were finches perched among cactus spines; yellow warblers busying themselves in the bushes; and many iguanas.

The sun began its descent, burnishing the landscape with gold. The sandy trail opened up to a large lagoon. And there, wading through the silence, was a pair of flamingos. Salmon-pink against the blue lagoon, they dipped like ballet dancers towards their reflections. One stepped close enough for us to hear it dabbling as it cupped its beak through the shallows. I began to understand why Darwin described the islands animals as strangers to man. So unafraid of our presence were they that it was as if we had walked into their Arcadian world unseen.

Darwin frequently put the animals naivety to the test. He sat astride the native giant tortoises and, using a few raps on the hinder part of their shell, discovered he could ride them. (He also noted that the young tortoises were excellent in soup.) He flung a marine iguana into the sea to see how it would react when frightened, and pulled a burrowing iguana out of its hole by the tail.

On our first evening we were served dinner before setting sail for Isabela Island. I later realised that this was to ensure that the food remained on the table. My stomach proved a less successful receptacle. The passage was unforgivingly rough and our boat listed so violently I thought I would roll out of my bunk. It was a relief at 6am to hear the running chain of the anchor and know that we had neared dry land.

It was time for our first snorkel. The clear turquoise water, sparkling under the equatorial sun, had every appearance of enticing warmth. But during the dry season (June to December) the Humboldt Current sweeps north from Chile, bringing an array of wildlife, but also cold water. It cant be that bad, I thought, Im used to frigid English beaches. The immersion was overwhelming; the cold gripped my body as the water filled my wetsuit. A chorus of yelps piping through my fellow voyagers snorkels told me that I was not alone in my sensations.

The islands most famous inhabitant, the giant tortoise

But I soon forgot about my shivering limbs. Almost immediately we were greeted by a couple of playful young sea lions. They wheeled and arced around us, diving low in a stream of bubbles before reappearing as if to ask why we hadnt followed. One put its whiskered nose up to mine and peered into my mask. They were as excited to see us as we them.

Almost every day we had an opportunity to snorkel, and never did it disappoint. Turtles were the highlight of one swim I gave up counting at 30. Some dived with graceful strokes, some surfaced to let out a puff of air, others allowed themselves to be dragged back and forth by the waves.

On another swim, I was astonished to come across a whitetip reef shark barely 6ft away. Seconds later I realised I was drifting above a school of dozens. And I had woken them up. I knew that reef sharks do not usually attack humans, but I wasnt sure if that would be true if they were disturbed. When I noticed that one was circling, carefully watching me with hollow black eyes and a thin crack of a smile, I decided it was time to move on.

See more here:

The Galpagos Islands: Darwin's inspiration