The Devon-registered Margaretha Maria, based at Newlyn in Cornwall, capsized and sank 55 miles off the Cornwall coast with the loss of all four crew in November 1997.

The accident report published on Thursday said the boat's winches were capable of lifting weights which would have made the vessel unstable when the nets were hoisted up.

The vessel would then have capsized, flooded and sunk, said the Marine Accident Investigation Branch (MAIB) report.

Vanished without trace

The Margaretha Maria vanished without trace after she left for a week-long fishing trip on 11 November.

A two-day search-and-rescue operation a week later failed to find any sign of the vessel.

Skipper Robert Holmes, 43, mate John Todd, 45, his son Kerry Todd, 24, and father-of-three Vincent Marshall, 33, who had been an experienced crew, all perished.

On 11 February 1998, the body of Mr Holmes, also a father-of-three, was recovered in the nets of another fishing boat off Lizard Point. The wreck of the Margaretha Maria was then found nearby.

Winches 'too powerful'

Underwater surveys for the MAIB report found there was nothing to suggest she had hit another object, but that her winch was "capable of hauling weights to the surface which could seriously affect the vessel's stability".

There had been about four tonnes of sand, shellfish and other debris in each of her nets, the report found.

The report also found that emergency equipment had not been working properly.

Two life rafts were damaged in the sinking and could not be used. The EPIRBs [emergency position indicating radio beacons], did not give off any signals and could have got caught up in the nets, the report said.

'Could happen again'

The MAIB recommended the Maritime and Coastguard Agency take four steps to try to prevent such an accident happening again:

• study the vessel reporting system now operated at Newlyn, to see if it should be implemented elsewhere
• highlight the potential dangers of large capacity winches
• check the actual sea-going stability levels of a beam trawlers
• review the stowage and performance of EPIRBs.

However, one of three widows of the lost crewmen, Moira Todd from Penberth, west Cornwall, warned that such an accident could happen again.

She said the report proved that beam trawler stability tests, carried out without fishing gear aboard and in still harbour waters, were "absolutely useless".

'Lessons being learnt'

"Every beamer out there is at risk," said Mrs Todd. "This has got to be sorted. Fishermen have got to know they are going to sea in relative safety.

"There is no doubt it is a dangerous game. But our men had no chance," she said.

However, Shipping Minister Glenda Jackson said lessons were being learnt from the tragedy.

"The MCA have fully accepted the MAIB's recommendations and are making good progress on implementation," she said.