Temperatures approached 40 degrees when the camera crew spotted a stranded, sun-soaked fisherman on an island surrounded by rough waters believed to be the remote Barranyi North Island off the coast of the Northern Territory.

Animal Planet host Jeremy Wade and his crew were searching for a rare fish called the Queensland grouper, for a segment for the documentary series "River Monsters," when the man emerged from a cave on an uninhabited island in the Gulf of Carpentaria, some 100 kilometres from the nearest town.

Dehydrated and disoriented, he was waving his arms and calling for help.

"He immediately came down to the water, and he's yelling out, 'Give me something to drink, give me something to drink,'" Wade said in the segment, which aired on Animal Planet this month.