Divers from Key Largo Volunteer Fire Department who had been assisting in the extensive three-day search operations discovered the body.

Stewart, 37, had been diving the steamer wreck the Queen of Nassau using a closed-circuit rebreather, as part of his work on the film "Sharkwater: Extinction". He had planned to complete and release this sequel to his multi-award-winning 2006 film "Sharkwater" later this year. 

Stewart went missing on the evening of 31 January at Alligator Reef, six miles off the coast near Islamadora.

The following day his sister Alexandra told the Toronto Star that Stewart had been on his third dive of the day. His dive-buddy had surfaced and “was struggling to get on board and then fell unconscious”. As the crew tended the diver, Stewart “surfaced and gave the OK sign, and then he was gone.”

Volunteers had joined in with the three-day search operations coordinated by the US Coast Guard, and an online campaign had raised some $200,000 in donations to help continue them. The hope was that Stewart, a diver since the age of 13 and an instructor from 18, was conscious but had been carried away by currents.

Stewart grew up in Toronto, graduated in biology and studied marine biology in Kenya and Jamaica. He became chief photographer for the Canadian Wildlife Federation until, on assignment in Galapagos, the practice of illegal shark-finning came to his attention.

He was 22 when he gave up his job to spend four years travelling extensively and filming undercover to make Sharkwater. The film went on to win more than 40 global film-festival awards and proved highly influential in rallying global opposition to shark-finning.

His next film "Revolution" built on the impact of "Sharkwater" with a warning of impending environmental apocalypse.

“We know Rob would want everyone to continue his mission to save the oceans and sharks. He believes men should live in harmony with nature,” said the diver’s parents, Sandra and Brian Stewart, in a statement.

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