The ship sets sail and we brace our legs against the swell, sweeping and mopping around the cabins. Countering the tilt we work quickly and silently, trying not to wake any crew who had been on watch the previous night. Not even celebrities and photographers are spared the daily 8am chores, the ship’s third mate, Amrit Bakshi, tells us later, laughing.

Clockwise from top: The Point Labatt conservation park lookout, mechanic Marc De Fourneaux fixes one of the ship’s small inflatable crafts, Laurence Nicoud from France, the only female cook for the Rainbow Warrior III, and volunteer deckhand Luca Lamont enters the bridge of the ship.

That was our first morning on board the Rainbow Warrior III, one of the world’s most recognisable sailing ships and a symbol of environmental activism. Visiting Australia for only the third time since it was custom-built for Greenpeace in 2011, the ship came to explore the wild and untouched waters of the Great Australian Bight, due south of the Nullarbor Plain.

Clockwise from top: Navigating waters around Greenly Island, Maria Martinez, the chief mate of the Rainbow Warrior III, first engineer Erik Mekenkamp enters the water nearby Massillon Island, and scientist Sam Owen completes his monitoring of marine species.

The bight is our wild, uncompromising underwater backyard. Kilometres of red earth and sand dunes drop off rugged cliffs into great expanses of deep, pristine ocean. A dive in these waters reveals another world. It’s a place where leafy sea dragons live and thousands of cuttlefish aggregate to breed. It’s home to the puppies of the sea – the endangered Australian sea lion – and a highway for the largest creatures in this world, also endangered, the southern right whale.

Clockwise from top: Erik Mekenkamp with an entourage of fish, a seastar nectria macrobrachia among a carpet of life under a ledge on the Great Southern Reef, and the cool waters of the bight which are home to bottom-dwelling plants, seaweeds, coral and sea sponges.

Environmental groups have been fighting to keep big oil companies from drilling in the bight.

To protect these creatures and the isolated fishing communities dotted along this coastline, environmental groups have been fighting to keep big oil companies from drilling in the bight since the Australian government granted BP four offshore exploration permits in 2011. BP has since pulled out, as did Chevron, however Norwegian company Equinor (formerly Statoil) plans to be drilling by October this year. Earlier this month, only days after the Rainbow Warrior left Australian waters, NOPSEMA (the regulatory agency for offshore oil drilling) approved an application for seismic surveys off the coast of Kangaroo Island and Eyre peninsula from 1 September for three months.

Sea Lions around Hopkins Island, South Australia. Sea lions use sound for communication, social interaction and navigation. Sound disturbances such as blasts from seismic testing can cause permanent hearing loss, which can have fatal consequences.

Lending its voice to the now-urgent movement to protect the bight, the Rainbow Warrior III came to showcase the unique marine life of this remote ocean pocket, where 85% of the species are not found anywhere else in the world. We joined the diverse crew of 30 as they sailed from Adelaide and Ceduna, exploring the remarkable but little-known Great Southern Reef.

A school of fish surround filmmaker and scientist Stefan Andrews.

A turbulent ocean greeted us as we neared Greenly Island. We were 30 kilometres west-south-west of Point Whidbey on Eyre peninsula, South Australia, and an eerie grey cloud clung to the island’s granite peak. As Michaela and the other three divers descended to depths of 30 metres, they found themselves between underwater mountains dressed in kelp that danced with the current. A curious sea lion came to investigate their strange-looking flippers. As they explored the ledges sheltered from the swell surge, an array of sea life was revealed – fish nurseries, rarely seen sponges, corals and an explosion of colour, shape and life.

Videographer Stefan Andrew rests after a dive in the waters around Massillon Island, part of the Nuyts archipelago off the coast near Ceduna, in the Great Australian Bight.

Over the course of a week, dive after dive revealed an abundance of life and plethora of species. Some difficult to identify as these areas have not been well-documented compared with other marine parks in Australia. When the divers surfaced, the questions began. How was the dive? What did you see? Any sharks?

Clockwise from top: Volunteer deckhand and environmental activist Luca Lamont learns the ropes from Manuel Marinelli, the view of the Great Australian Bight from inside the galley, and Lamont.

Similarly, when the underwater remote operated vehicle (ROV) trawled the ocean floor, a genuine interest in those seldom-explored deep underwater environments was palpable among those on board.

Appreciation for this valuable ecosystem permeated the floating micro-community and it was infectious. We found it impossible to remain indifferent after what we witnessed above and below the surface of the Great Australian Bight.

The Rainbow Warrior III as sun sets over the waters of the Great Australian Bight, off the coast of South Australia. The ship is one of the greenest in the world and runs off wind power around 75% of the time depending on conditions.

For photographers, unless you’re covering breaking news or sports, it’s rare to work alongside each other for extended periods of time. Looking back now, that first morning cleaning the floors and smelling of vinegar was the beginning of a unique shared experience in the untamed Australian marine environment, one we feel compelled to share.