It is an otherworldly scene. A paper nautilus floats on a piece of ocean debris after a volcanic eruption in the Philippines, its orange eye bright against the black water, its parchment-like shell curled in a perfect spiral, with specks of light falling like raindrops on the image.

And for this photo of a paper nautilus, a type of octopus, Jialing Cai has been named the Ocean Photographer of the Year 2023, beating thousands of photos submitted to the competition which aims to display the beauty of the oceans and the threats they face.

The marine biologist and amateur photographer captured the photo on a blackwater dive -- a night dive in the open ocean, which uses floodlights to attract the ocean nightlife.

Thousands of entrants submitted underwater and coastal images, as well as pictures captured by drone, to the competition, organizers said.

Some of the awe-inspiring entries to the contest feature a polar bear cub contending with the fragility of melting ice, a scuba diver exploring the underside of a gigantic iceberg and diving gannets.

Will Harrison, editorial director of Oceanographic Magazine and the Ocean Photographer of the Year, said in an email sent to CNN Thursday: "The range and quality of submissions entered into this year's competition is special. From world-class drone images of megafauna to breath-taking underwater images of deep-dwelling ocean wildlife, the full spectrum of ocean life is brought to life like never before.

"This is an extraordinary collection of photography from an extraordinarily talented group of ocean photographers: divers, surfers and sailors uniting to dazzle the world."

The images from this year's competition, produced by Oceanographic Magazine, in partnership with Blancpain, Arksen and Tourism Western Australia, will be on display for five months at the Australian National Maritime Museum in Sydney from November 17.

A selection of the winning and highly commended images can be seen in the gallery above.