I approach him cautiously and he slowly turns his head in my direction, remarkably unafraid. Even when I kneel down beside him, my face one metre away, he stares at me, lethargically blinking his eyes.

That’s what happens to marine iguanas living on the remote Galápagos Islands — no fear of man. This sense of security is shared by all animals living here. You can float face-to-face with penguins, walk down a pathway with a masked booby and sit next to a 300-kilo tortoise as he munches on banana leaves.

One thousand kilometres off the coast of Ecuador, the Galápagos archipelago was formed by underwater volcanic eruptions millions of years ago. Isolated in 50,000 square kilometres of the Pacific Ocean, thirteen major islands, six small islands and forty islets harbour a variety of species. More than half of the plants, one third of the fish and most of the reptiles are found nowhere else on earth.

Because the islands were never attached to the mainland, species that migrated had to adapt to their new environment. Through many generations, they evolved into a subspecies or an entirely new species (Darwin’s theory of evolution by natural selection in its simplest terms). For example, Galápagos tortoises on dry islands have a longer neck and curved shell necessary to reach cactus pads while tortoises in wetter areas have a domed shell, protecting the animal as it moves through thick vegetation. The flightless cormorant, Lava heron and Galápagos Fur Seal are other endemic species found on these isolated Ecuadorian islands.

There are few places in the wild, if any, where people can commune with a variety of animals that feel safe and unthreatened. Wildlife rehabilitation centres and some game reserves (where animals are attracted by salt licks) offer a chance to interact with wildlife, but these experiences aren't truly natural. In the Galápagos, boats take visitors from one island to the next, offering a unique opportunity to meet a variety of wildlife. Although people aren’t allowed to touch or pet wildlife in the Galápagos, you can get very close to animals and sometimes, they’ll come to you.

It was the marine iguana (Amblyrhynchus cristatus) at Punta Espinosa that gave me the first of many face-to-face encounters during the week-long cruise. This sea-going lizard is endemic to the Galápagos and lives on many of the islands. Fernandina Island hosts the largest colonies in the Galápagos, where they bask in the sun, feed near shallow reefs and dive for seaweed. Scientists calculated that the colony of 2,000 marine iguanas on Punta Espinosa, a point on Fernandina Island, feast on 28 tonnes of seaweed annually.

Charles Darwin referred to the marine iguana as "a hideous-looking creature, of a dirty black colour, stupid, and sluggish in its movements." I couldn’t disagree more. With slow deliberate movements, salt encrusted heads and stubby faces, they are rather cute. When they excrete salt by blowing it through their nostrils, they resemble miniature dragons. And when their scales are wet, a reddish tone colours their body. Darwin should have jumped in the water with them.

For two days we had snorkeled after lunch, following stingrays fluttering along sandy floors, scurrying behind schools of moorish idol and exploring sunken craters teeming with varieties of tropical fish. It was while defogging my mask that a marine iguana surfaced in front of me.

We look at each other. Reptile and human. Scale and skin. Sea and air. I smile and he stares straight ahead, the expression of a wise, old sage on his scaly, wrinkled face. Unhurried by the tumbling waves, he lingers on the water as if deep in thought.

Eventually he dips his head back under the water, and I pull on my mask to follow him. For a while he crawls along the ocean floor. A few times I dive down, but mostly I hover above, not wanting to disturb his forage.

I follow him as he swims in a snake-like fashion, drawing in his legs and wiggling his body from side to side. His tail becomes a paddle, propelling him forward. Every five minutes, he slowly swims to the top and I surface with him, side by side. He leisurely looks around — a human, the rocky shoreline, a boat in the distance — nothing unusual. He plunges into the water and I re-immerse myself into his world.

It’s only the larger males that venture into the open waters to dive. Others feed along the rocky shoreline as the tide pulls out. It is the male marine iguanas that can dive down to 12 metres and stay submerged for up to one hour, slowing down their heartbeat to make a long dive.

The males wait till they have warmed up in the mid-day sun before starting to feed. It’s also the time that Galápagos visitors take a break from the equatorial sun and jump into cool waters with snorkel mask and fins. I have forgotten about the boat, the rest of the group and the hike that afternoon. I’m swimming with a marine iguana.

The iguana surfaces and I join him again. Our heads pop out of the water and our eyes meet. As if a wave of reality hits the iguana, he dips underwater and swims away from me. He heads towards waves crashing against the rocky shoreline. I can’t follow.

Enchantment shattered, I wonder what made him swim off. How quickly you get spoiled in the Galápagos. A behaviour that might appear leery by Galápagos standards is unheard of globally. Perhaps the marine iguana sensed a better seaweed patch near the rocks. Or maybe I seemed too large a creature with a snorkel sticking out of my head.

There isn’t much that intimidates animals in the Galápagos, least of all, the Great Frigatebird (Fregata minor). Even during courtship, you can stand nearby as the male inflates his a bright red pouch much like a balloon (takes up to 20 minutes), opens his wings and utters an eerie call in hopes of attracting a female. At Darwin Bay on Genovesa Island, the best area to get close to courting and nesting Frigatebirds, one male was having bad luck. Each time he spotted a female, he turned his red pouch and wings skyward. Once in a while, a female would swoop down, almost touching his beak, and then fly off again. The more he was rejected, the more vigorously he shook his wings. His misfortune was my luck — the courting display is enchanting to watch.

As captivating is seeing these birds with a 230 cm wingspan, in flight. Unable to dive underwater, they catch most of their food by stealing it midair from smaller birds and even their own kind. This form of piracy requires precise maneuvering.

The only bird that has no natural enemies is the Galápagos hawk (Buteo galapagoensis). The only raptor on the islands, it is virtually fearless of man. I walked the entire length of Gardner Bay beach at Espanola island with an immature raptor a few metres away. Where else can you get that close to a bird of prey in the wild?

I was initially drawn to this mottled brown bird by his panicky squawk. I was concerned and followed him as he hopped along the sandy beach and flew from log to shrub perches. It was when he reached his mother and she quickly flew off, that I realized he was being weaned.

Earlier that day I spotted another Galápagos hawk, who was more reluctant upon my approach. Animals are like humans in that sense. Some people love a crowd, others like peace and quiet. On land, sea lions (Zalophus californianus) are much the same. Some shuffled away at a distance of two metres, while others let me lay down right in front of them. It’s best to approach sea lions, and all other species, low and slow. When walking upright, a human silhouette is much scarier than approaching them at ground level.

In the water, sea lions lose any timid nature they might have. On the beach they’re resting, but in the water they like to play. Most days, I encountered sea lions while snorkeling and each time they were a great source of amusement.

I remember a sea lion pup that first nudged me. He came right up to my face, swerving at the last second. He rolled, twisted and turned around me and I simulated and followed his movements. This grew into a game of tag. We swam around a rock outcropping, sometimes doubling back and surprising each other. Later on, two more pups joined in the game.

I did keep a distance when a sea lion mother and her pups approached. As with any wild animal, caution must be taken. Even a playful pup could take a nip. It’s difficult to know the perfect balance and it’s best to check with your guide. Animals seem tame in the Galápagos and it’s easy to forget they are wild. That’s the magic of these remote islands and also the threat.

More tourists are visiting these fragile oceanic islands, five of which are inhabited with a population that increases annually. The growing number of people adds to the introduction of species that compete with and destroy native flora and fauna. The plants that disturb wetlands, for example, destroy nesting habitat for birds. Domestic goats, cattle and donkeys used for agriculture on the inhabited islands, trample nests and compete for food. Feral cats, goats and pigs represent a great danger to hatchlings. Once introduced, these species are difficult to control.

Precautions are being taken with tourists. A naturalist guide accompanies every boat to ensure visitors stay on the trails and do not disturb the animals. When tourists board the boat after visiting an island, they must wash off to prevent transporting a plant seed or insect to another island.

Still the threat remains. When I visited, it wasn’t possible to meet the giant tortoises in the wild. We saw them at the research station, in an enclosed area. I remember standing next to a tiny cactus finch feeding on a prickly pear cactus; a pair of red-footed boobies perched on a branch; a great frigatebird displaying his red pouch skywards... I hope to see them all in the wild when I return.