A mini-submarine on a UK-led research expedition has made an emergency ascent from 100m beneath the surface of the Indian Ocean after smoke filled its cockpit.
The British scientist and American pilot on board were safely rescued from the vessel and are recovering on its mother ship off the Seychelles, where they are investigating climate change.
The Nekton Mission said it was looking into the cause of an electrical fire but the team was expected to be back in the water on Wednesday. Emergency procedures had worked well, it added.
The sub was descending off Aldabra Island when pilot Robert Carmichael smelled smoke.
He said he quickly fitted breathing masks to his scientist Molly Rivers and himself, then began an emergency rise to the surface as the oxygen indicator fell to zero.
"It's the greatest fear: fire inside the cockpit,” he said. “Your greatest fear. Where are you going to go?"
A member of the sub's support team said it took 23 minutes to reach the surface.
The vessel is one of two involved in Sky TV's Deep Ocean Live programme, part of a two-year campaign by the British broadcaster to focus attention on the state of the world's oceans.
The Nekton Mission - led by the Nekton Oxford Deep Ocean Research Institute - is documenting changes taking place beneath the Indian Ocean that could affect billions of people in the surrounding region over the coming decades.
The mission has been dogged with bad luck since it left Victoria, the Seychelles capital, at the beginning of March.
Poor weather forced a change in route, an underwater drone was temporarily lost when the ship's propeller cut its cable, and other key equipment has malfunctioned.
The seven-week expedition is expected to run until 19 April.
