An accident report says three fishermen from Dorset died because their incorrectly stowed liferaft failed to float free and automatically inflate when their vessel sank.
Had the raft done so it was "entirely possible" that the fishing boat's skipper David McFarlane, 35 (pictured) and his crewmen, Jack Craig, 21, and Robert Prowse, 20, would have been saved, the report said.
The three men had set off from Weymouth on the wooden potting vessel Purbeck Isle when the heavily-loaded boat suddenly foundered nine miles off Portland Bill in Dorset on the morning of May 17 last year.
The report from the Marine Accident Investigation Branch (MAIB) said the boat went down so quickly that the fishermen were unable to broadcast a 'Mayday', collect their lifejackets from below deck, or manually launch the vessel's four-man liferaft prior to entering the water.
As the vessel sank, the hydrostatic release unit (HRU) used to secure the liferaft in its cradle on the wheelhouse roof activated as designed, but the raft failed to float free and sank to the seabed. As Purbeck Isle was not fitted with an emergency position indicating radio beacon or similar emergency distress signalling device, more than seven hours elapsed before the coastguard was alerted.
The report said:
"By this time, all three fishermen had most probably already succumbed to the effects of the cold choppy seas.
"The investigation found that although the liferaft's HRU activated as designed, Purbeck Isle's liferaft failed to float free and automatically inflate because it had not been correctly stowed or secured in its cradle on the wheelhouse roof.
"Because the liferaft canister did not fit snugly into its cradle, the skipper had applied additional lashings to prevent it from falling off the wheelhouse roof in heavy seas. These additional lashings had been intertwined with the liferaft's main lashing rope and they prevented the raft from floating free.
"However, had the liferaft floated free, it would not have automatically inflated because its painter (the line that anchors a boat to a dock) had not been attached to the HRU's weak link.
"The liferaft had also been stowed upside down in its cradle. This would have allowed water to build up inside its canister, reducing its inherent buoyancy and increasing the likelihood of its inflation mechanism suffering from corrosion and failing."
The MAIB said:
"Had Purbeck Isle's liferaft floated free and inflated as the vessel sank, it is entirely possible that three lives would have been saved."
The report said the body of Mr McFarlane, who was from Weymouth, was found the day after the sinking. He was entangled with the ropes attached to Purbeck Isle's two lifebuoys and was wearing a tee shirt and jogging bottoms.
Later on May 18, the wreck of the Purbeck Isle was located. The search for the two missing fishermen was called off on May 19.
Nearly two months later, on August 9, the body of Mr Craig, who was from Portland, was recovered by a trawler from the seabed in Lyme Bay, Dorset. The body of Mr Prowse, from Weymouth, has not been found.
In its report, the MAIB strongly advised fishing vessel owners to ensure liferafts are stowed and secured properly.