ANTARCTICA (AFP) — The swimsuit-clad tourists leap into the icy water, gasping at the shock, and startling a gaggle of penguins.
They are spectators at the end of the world, luxury visitors experiencing a vulnerable ecosystem close-up.
And their very presence might accelerate its demise.
Antarctica, a vast territory belonging to no one nation, is a continent of extremes: the coldest place on Earth, the windiest, the driest, the most desolate and the most inhospitable.
Now, it's also a choice destination for tourists.
All around Half Moon Island, off the Antarctic Peninsula, blocks of ice of all sizes float by on a calm sea, their varying forms resembling weightless origami shapes.
On this strip of land, that juts out of the Antarctic Polar and towards South America, visitors can see wildlife normally only viewed in zoos or nature documentaries along with spectacular icy landscapes.
The ethereal shades of white that play across the pillowy peaks change with the light, acquiring pastel hues at dawn and dusk.
"Purity, grandeur, a scale that's out of this world," says Helene Brunet, an awestruck 63-year-old French pensioner, enjoying the scene.
"It's unbelievable, totally unbelievable. It's amazing just to be here, like a small speck of dust."
AFP joined the 430 passengers on board the Roald Amundsen, the world's first hybrid electric cruise ship, on its maiden voyage in the Southern Ocean.
"It's not your typical beach, but it's awesome to do it," says a numb Even Carlsen, 58, from Norway, emerging from his polar plunge in the 37.4 F water.
When tourists go ashore, bundled up in neon-colored windbreakers and slathered in SPF50 sunscreen, they have to follow strict rules: clean your personal effects so you don't introduce invasive species, keep a respectful distance from wildlife to avoid distressing them, don't stray from the marked paths and don't pick up anything.
"We mucked up the rest of the world. We don't want to muck up Antarctica too," says an English tourist, as she vacuums cat hair off her clothes before going ashore.
'Heart of the Earth'
The Antarctic peninsula is one of the regions on Earth that is warming the fastest, by almost three degrees Celsius in the past 50 years, according to the World Meteorological Organization — three times faster than the global average.
In March 2015, an Argentinian research station registered a balmy 17.5 degrees Celsius, a record.
"Every year you can observe and record the melting of glaciers, the disappearance of sea ice... (and) in areas without ice, the recolonisation of plants and other organisms that were not present in Antarctica before," said Marcelo Leppe, director of the Chilean Antarctic Institute.