Five men and a woman drowned when the 100-ton scalloper Pescado sank in seconds in 240ft of water 13 miles offCornwall after sailing from Falmouth on 25 February 1991.
According to regulations, the vessel should have had two life-rafts on board - but there was only one, lashed to railings above the crew's quarters, Francis Gilbert QC, prosecuting, told Bristol Crown Court.
It should have been fitted to a regulation cradle, which would have allowed the 10-man raft to release automatically, float to the surface and inflate during a sinking.
The covered raft would have been available to the crew had it been properly fitted, he told the jury.
Fitting of the life-raft, made in the 1970s, was supervised by Joseph O'Connor, 44, who, with Alan Ayres, 56, has pleaded not guilty to six charges of manslaughter arising from the death of the crew.
Mr O'Connor and Mr Ayres were respectively managing agents and director of Guideday Limited, the company which owned the Pescado.
While he was skippering and managing the vessel, Mr O'Connor allowed the raft to remain on it, Mr Gilbert said on the second day of the trial.
Mr O'Connor supplied the life raft to the Pescado after a crew member complained there was none on board. He took the moss-covered raft from his garden and lashed it to the Pescado's rails. Tied on in that way, its automatic release mechanism was unable to work, the jury heard.
The jury watched police video footage of the life-raft being taken from the salvaged wreck in September 1993, and inflated. Some of the crew would have survived if the required safety equipment had been available to them, said Mr Gilbert.
The trial continues onMonday.