Adam Nicolai Tribute Onlinetributes.com.au

Adam and his friend Justin were lost at sea at the weekend.  How sad for them and their families.

South Australian police have confirmed a body has been found where two

fishermen are missing after a boating accident off Yorke Peninsula.

The body was found near an oyster reef.

A lifejacket and debris from a sunken fishing boat were found earlier, six kilometres off the coast.

A third man, Andrew Pisani, 33, swam for several hours in the dark and was found on the beach near Stansbury just after 2:00am ACST, delirious and suffering from hypothermia.

Senior Sergeant Dave Roy from Yorke Peninsula police says the two missing deckhands, both 28, are originally from Mt Gambier but have been living in Yorketown.

"As time progresses obviously the chances ... are going to reduce," he said.

Friends of a surviving fisherman on Yorke Peninsula are believed to have found the sunken boat, six kilometres off-shore.

Tim Harris, a friend of Mr Pisani, found a lifejacket this morning and then the boat about a kilometre away.

"We found the net with the buoy on the end of it and the boat's on the end of that, as far as we know at this stage until police dive down," he said.

Mr Pisani's brother Damien has told ABC News that his brother is very shaken and is being treated for hypothermia and gashes to his legs from razor fish.

Mr Pisani is being treated in the Yorketown Hospital and is in a stable condition.

Alan Rushbrook from the Yorke Peninsula Council says the community response has been overwhelming.

He says news of the accident has shaken local people.

"The mood is one of concern and shock, everyone goes out on their boats and they realise that accidents can happen, and it's very sobering and reminds everyone of the potential dangers out on the water," he said.

Local farmer Ted Buttfield, a friend of Mr Pisani, says he made an incredible effort.

"Phenomenal. He did an exceptionally good job. I would imagine that he is probably very exhausted now," he said.

The police helicopter, STAR group officers and water police are searching the area.