A southern royal albatross, its massive 3.5m wingspread making it seem like a black and white Boeing 767, swooped just 2-3m above our heads as we stood on the heights of Enderby Island.
It appeared to be heading for a touchdown on a flat area a short distance away where another albatross was standing, its beak raised like an avian air traffic control officer. But at the last second, the landing was aborted.
Meanwhile, more of these flying giants were circling the upland plateau, giving it the appearance of a busy commercial airport.
Enderby Island, at the northern tip of the Auckland Islands, 450km south of Invercargill and well into the Sub-Antarctic region, has little human presence.
In fact, when we arrived on the expedition ship Orion, the resident human population on the whole of the Auckland Islands was four researchers doing a three-month stint studying the amazing wildlife.
But it has most of the facilities you'd expect to find in any major city. As well as the royal albatross airport there's a yellow-eyed penguin motorway, a bull kelp supermarket, the bustling sea lion downtown area, the shag towers seafront apartments and a beautiful botanical garden full of rare plants.
What's more, most of the customers for these facilities are unique to the Auckland Islands and among the rarest of their kind in the world.
The entrance to Enderby Island is Sandy Bay - which, unusually in this part of the world, is indeed sandy - where a small cluster of battered little huts signals the presence of the research station.
But the first thing you hear, see and smell is not human activity but the colony of New Zealand sea lions - also known as Hooker's sea lions - using the nice comfortable beach as the species' major maternity hospital.
This is, as you come to expect down here, the rarest sea lion in the world and the beach is home to several thousand of them, a significant chunk of the global population.
While still on the Orion and some distance offshore we could already hear the bellows of the big males, called beachmasters, who rule the colony, and as we got closer in our Zodiacs the noise got louder and we could see them jostling for position.
Later we were allowed to wander along the top of the grassy foreshore for a close up view of the sea lion CBD - the animals here have been the subject of a scientific study for the past 12 years and so are used to humans - which was a hive of activity.
Much of the action involved the big beachmasters, weighing in at 400-500kg, each with a harem of females which they protected jealously, which is presumably why most of the females had newly born pups.
Hanging around on the fringes were the wannabe beachmasters, big lads keen to get in on the action.
The beachmasters were constantly bellowing warnings at each other, and at any of the wannabes, often reinforcing the message by butting up against each other in a demonstration of strength and opening their huge mouths to display the rows of teeth.
There was little serious fighting. One of the bigger wannabes had a huge wound on his chest which to my eyes looked bad enough to be fatal but Liana Joseph, one of our naturalist guides, said it would heal quickly. "They've got amazing immune systems."
Amid this constant macho head-butting, the thousands of females basically got on with the business of day-to-day living, suckling their pups, getting a little shut-eye, occasionally heading out to sea to feed, frequently fighting off the attentions of randy males and now and then allowing their beachmaster to cuddle up.
The pups, meanwhile, were just being pups, wandering curiously around, always looking for food and sometimes getting a nip if they tried suckling from the wrong female, playing with each other and keeping a wary eye on the vicious skuas which patrolled the beach in pursuit of anything edible.
Although most of the action was on the beach, some animals, mostly young males, would climb up the bank from time to time, cross a big grassy area and make their way through the stunted rata forest in search of a quiet place to rest.
It was mildly disconcerting, as we explored the island, to hear great belches and bellows coming unexpectedly from a clump of nearby trees.
For humans, access to the island is tightly controlled by Department of Conservation rules. Numbers are strictly limited and visitors have to keep to a narrow boardwalk across the top of the island.
But to get access to the boardwalk it's necessary to cross the yellow-eyed penguin motorway and, naturally enough since this is the world's rarest penguin, you can do that only when there is no traffic.
As it happens, my group of about 35 explorers was about to set out when there came a cry that a penguin had just landed on the beach so we had to wait while it made its stately way up the bank and along the grassy motorway into the rata and tree daisy forest where it probably had a youngster to feed.
I saw several more later, some walking along the motorway, often in pairs, and quite a few standing on the cliffs around the shore, presumably contemplating a hard day's fishing in the icy waters.
To my eyes they look sort of washed out compared to other penguins, less sharply black and white, their coats a little pale and their heads definitely a light yellow, almost matching their eyes.
Anyway, once the motorway was free of traffic we made our way across it and on to the boardwalk. Walking across Enderby Island we saw several of its small birds: red-crowned kakariki, pippets, tomtits, bellbirds, tui and silvereyes.
But the stars of the show were, of course, the southern royal albatross - one of the rarest of these amazing ocean wanderers. Most were sitting alone on their nests, some only a few metres from the boardwalk, seemingly unconcerned at our presence, waiting for their mates to return from their ocean feeding.
There were also a few young adults, too young to breed but old enough to look after themselves. Three of them were having a get-together near the boardwalk, preening each other, their bills set in permanent smiles, looking as though they were exchanging gossip about their experiences circling the great Southern Ocean.
The upland plateau where the albatross nest is also the island's botanical gardens with a remarkable display of plants.
I had expected the Sub-Antarctic islands to have little in the way of flowers but I couldn't have been more wrong.
During the brief summer in this part of the world the island explodes into colour. Towards the end of the boardwalk there was a huge area of magnificent yellow bulbinella flowers, slightly past their best, but still a spectacular sight.
And guide Liana, an authority on plants, pointed out equally lovely blooms of pink gentiana and purple myosotis as well as the red rata blossoms, white tree daisies, the intriguing Macquarie Island cabbage - eaten by many a shipwrecked mariner - clumps of sedge and tussock waving in the breeze and lots of weird-looking liverworts.
The plant life around the coast is equally rich, as we discovered during a Zodiac exploration, with huge masses of bull kelp and lots of red and green algae.
It was pouring with rain during the Zodiac trip - well, it does rain much of the time - but we still managed to see quite a few birds, including yellow-eyed penguins standing on the shore and, most exiting of all, a few of the flightless Auckland Island teal - the wold's second rarest duck - picking up food in the kelp supermarket.
The coast in this part of the Enderby Island consists of steep cliffs of extraordinary vertical columns of lava, like great hexagonal columns, painted with mosses, lichens and bird droppings so they look like a giant work of art.
The cliffs also serve as apartment towers, housing a few gulls, and even a couple of penguins huddling in caves, but mainly for the delightful Auckland Island shags, with their fantastic purplish eyes and bodgie hairdos.
If these apartments were in Auckland City, instead of the Auckland Islands, they'd be worth a fortune. But they're still highly sought after.
Indeed, our expedition leader Mick Fogg, who may have a part-time job as an estate agent, observed, "This is probably the most attractive spot in the Sub-Antarctic. Enderby Island is known as the banana belt of the Auckland Islands. It's the place to be."
Further information: Orion Expedition Cruises visits the Sub-Antarctic islands, including Auckland, Campbell and Macquarie Islands, The Snares and Stewart Island. over the Christmas-New Year period.
Jim Eagles travelled to the Sub-Antarctic islands as guest of Orion Expedition Cruises.