Boobies. Everywhere you look. Sarah, the naturalist at the tiller of our Zodiac tender, has some sage advice as eyes and cameras are trained skyward at the dozens of handsome Brown Boobies hovering a few feet above: “Mouths shut tight as you look up. Or find out why, the hard way.” We’ve left the mothership, Ponant’s Le Jacques Cartier, for a mission to the Lacepede Islands, our first foray into northwestern Australia’s extraordinary Kimberley region.

There are good reasons why you’d join an expedition cruise to see the Kimberley coast, a region named by Europeans in 1879 after the First Earl of Kimberley, then Secretary of State for the Colonies. Most of us don’t have access to a private boat that’s skippered by someone with experience sailing in northwest WA, and certainly not one who’s also possessed of a pirate’s sense of adventure.

Then there are the crocs. Saltwater crocodiles are everywhere along the 12,000km of Kimberley coastline – and this is the most practical option to find them without running afoul of them.

There are 18,000 breeding pairs of Brown Boobies at the Lacepedes, the largest single population on Earth. The lone Masked Boobie I spot with my binoculars doesn’t know it isn’t a Brown Boobie, and it’s easy anyway to get lost in a crowd. Other birds here include Australian Pelicans, Crested Terns, Eastern Reef Egrets, Silver Gulls, Lesser Frigatebirds, Pied and Sooty Oystercatchers. And 20,000 Roseate Terns. A green turtle (Chelonia mydas) pops its head up nearby to suck down a noisy lungful of air, but suddenly there are a hundred more, flapping lazily about the seagrass shallows of the biggest breeding site for green turtles in Western Australia. A moment for Sarah to point out that a green turtle doesn’t have a green shell but is layered in greenish fat, the result of its 100% seagrass diet, unique among the planet’s seven species of sea turtle.

The lecture which follows on board Le Jacques Cartier underscores a feature of this trip – naturalists able to distill years of knowledge and experience into a sixty-minute talk. We hear from Remi Bigonneau, who has a degree in Management & Conservation of a Protected Area. “Think of seabirds as the ‘Top Guns’ of the sky. All the ones we’ve seen today are mostly white, or grey, or dull brown. No energy wasted developing colourful plumage and fancy feathers. Seabirds are the all-business aviators, adapted to survive the oceans – diving for food alongside other predators, nesting on crowded and dangerous shores patrolled by other birds, crocodiles, and seals. Breed where they’ve always bred because it’s proven successful. Often a pair will incubate one egg, raise one chick, and many share hunting and parenting duties. Almost 11,000 species of birds worldwide, and only 340 of them are seabirds.”