The deaths of two men from carbon monoxide poisoning on a boat moored in Hobart were "tragic and completely avoidable accidents", coroner Simon Cooper says.
A friend discovered the bodies of Gregory John Burling, 58, of Newnham, and Brian Owen Daley, 56, of Mowbray on his 10-metre cruiser on 11 January 2016.
The vessel was moored at the Gepp Parade Marina Prince of Wales Bay.
The pair had spent the previous night on board the vessel after making the journey from Wineglass Bay.
An investigation found the pair had died of carbon monoxide poisoning as a result of a poorly installed portable power generator and the absence of a carbon monoxide detector.
Coroner Cooper found the generator was in an enclosed space, its muffler was severely obstructed by a shower curtain and the exhaust had a very long home-made extension which was "wholly unsuitable for the task for which it was designed".
He said this caused the generator to leak gas into the boat's cabin where there was no device to alert those on board.
In his findings, Coroner Cooper said it was apparent the "deaths were entirely avoidable", and he recommended that all boats with enclosed cabins and petrol motors of any type be fitted with a carbon monoxide detector.
He also recommended that all generators be used in accordance with manufacturer's recommendations and not be installed in a confined space.
The fatal journey had begun on January 9 when the boat's owners Mr Barry Lowe and Mr Burling set off from Bicheno to Hobart along with Mr Lowe's seven-year-old daughter and Mr Daley.
Near midnight, while anchored at Wineglass Bay, Mr Lowe's daughter started fitting and needed to be airlifted to the Royal Hobart Hospital.
She was later discharged after a blood test and observation.
Meanwhile, Mr Daley and Mr Burling continued on to Hobart and arrived at the marina on Sunday evening.
Coroner Cooper said toxicology reports showed the pair had spent the evening drinking and that the effect of the alcohol likely masked the effect of the carbon monoxide concentration.
After failing to contact the men by phone, Mr Lowe went to the marina the next morning where he found them both deceased.
