An elderly woman has been found dead after a boating accident in Tasmania.

She was one of three people thrown from the vessel into a stretch of water known as the Marion Narrows at Marion Bay in the state’s southeast about 11.45am on Wednesday.

Only one passenger remained inside the 4.5m fibreglass runabout, and they called emergency services from their location about 600m offshore.

Police commander Jason Elmer has described a boating death in Tasmania as a ‘freak accident’.

Initial reports suggested the boat had capsized, but police now believe the boat veered to its side after getting caught in the chop of a passing vessel.

“We think they’ve either hit a wave or some chop from another boat and that has potentially caused their boat to veer to one side, which has then caused the three people to be thrown into the water,” southern district commander Jason Elmer said.

“This appears to have been a freak accident.

Onlookers on a nearby vessel rushed to their aid but were only able to locate and retrieve two men, who were hospitalised with non-life threatening injuries.

The search for a woman in her 70s ended when a body was found in the water a short time later.

All three passengers were believed to have been wearing personal flotation devices.

“This is a tragic outcome for this woman’s family, her friends and her loved ones and our thoughts and condolences go out to them at this time,” Elmer said.

“In acknowledging that this is a terribly difficult time for the family and loved ones of the victim, police would like to thank those members of the public on nearby vessels who came to the assistance of the group. Their actions have helped prevent potential further tragedy.”

The incident comes days after a young French man was found dead after jumping off a boat into the water at Hobart‘s waterfront.

The 23-year-old was onboard a scientific vessel docked near Princes Wharf 1 when he jumped into the water sometime around 3.55am on Tuesday. His body was found about 7.45am not far away, near Franklin Wharf.

A day earlier, three men, aged 64, 67 and 74, were found dead in waters of South Australia after they failed to return from a boating trip in New South Wales.

They were recovered from waters off the Beachport boat ramp late Sunday night following an eight-hour search operation.