Two friends dead after boat tragedy

A man tried in vain to save his two elderly mates from death after a boat capsized near Hobart while they were crabbing.

The trio were trying to retrieve a crab pot from waters off Carlton Bluff, east of Hobart, when a breaking wave struck their 4.9-metre boat before 7am on Sunday, police said.

A 51-year-old man, from Dodges Ferry, swam to shore before returning to the water and dragging his friends to shore.

But he couldn't save the Lewisham man, 81, and the Dodges Ferry man, 82.

Inspector Matthew McCreadie told AAP the shoreline was at the bottom of a steep, 40m high cliff face, meaning emergency services could only get the survivor out by helicopter.

He was taken to Royal Hobart Hospital with minor injuries.

Police have retrieved the bodies of the deceased.