A jury at Preston Crown Court has been shown dramatic film of the rescue of a Chinese cockle picker on the night at least 21 people died at Morecambe Bay.
Twenty-three cockle pickers may have died in February 2004
The video footage, taken from a helicopter, showed Li Hua waving his arms frantically before being saved from a sandbank by a lifeboat crew.
The victims were part of a team caught by the incoming tide off Hest Bank at Morecambe Bay on 5 February 2004.
Lin Liang Ren, from Liverpool, denies 21 counts of manslaughter.
Li Hua had tried to save a friend before being rescued, the court heard on Tuesday. His friend drowned.
Tim Holroyde QC, prosecuting, said: "Li Hua had only been in Liverpool for a few days and this was the first time he had been cockling. He had one friend, whom he called Brother Wen.
"He says that after picking one small bag of cockles, he found it was too cold and dark to continue and so walked back to the shore."
He was called on his mobile by Brother Wen, who said he was stuck in the sea, Mr Holroyde told the court.
"Li Hua, who can swim, ran to try to rescue him. He swam across the first channel and was trying to swim the second channel to get to his friend when the waves became too big for him to go any further.
"He went to a higher area of sand, Priest Skear, which became smaller and smaller as the sea closed in," Mr Holroyde said. Li Hua was later rescued.
Zhao Xiao Qing denies perverting the course of justice
The court heard that a number of the surviving cocklers were arrested and taken to local police stations, where Lin Liang Ren, with his girlfriend Zhao Xiao Qing at his side, told them what they should and should not say.
Mr Holroyde said: "No one was to mention that he was the boss. They were to name one of those who drowned as being the boss."
The court was told it was "highly likely" that two other cockle pickers died in the tragedy, though their bodies had never been found.
Mr Holroyde described the workers as vulnerable illegal immigrants who were dependent on others for their livelihood and in no position to complain.
The court heard that most of the cocklers, who lived in one house on Priory Road in Liverpool, came from a farming background in China but had learnt their new trade on the job.
Lin Liang Ren also denies perverting the course of justice and conspiracy to facilitate illegal immigration.
Zhao Xiao Qing, 20, from Liverpool, denies perverting the course of justice and facilitating illegal immigration.
Lin Mu Yong, 31, from Liverpool, a cousin of Lin Liang Ren, denies an immigration offence.
Father and son David Anthony Eden snr, 62, from Irby, Merseyside, and David Anthony Eden jnr, 34, from Prenton, Merseyside, also deny immigration charges.
The trial, which is expected to last between four and six months, continues.