A Panamanian man who survived being stranded in the Pacific for 28 days and watched two friends die is suing the owners of a cruise ship that failed to stop and offer help.

Adrian Vasquez, 18, and fellow companions Elvis Oropeza, 31, and Fernando Osorio, 16, became stranded at sea after their boat's motor broke on a fishing trip off the coast of Panama on 24 February.

The men drifted at sea for 16 days before seeing a Princess Cruises ship moving close to the fishing boat.

Adrian Vaquez drifted for 28 days.

Mr Vasquez said they had signalled for help with a red jumper, but the cruise ship did not stop.

Both Mr Oropeza and Fernando Osorio died before Mr Vasquez was found 12 days later near the Galapagos Islands, almost 1000km off the mainland.

He said that he survived due to a rainstorm which topped up his supplies.

Mr Vasquez's lawyer, Edna Ramos, said the lawsuit contains eyewitness reports from two of the cruiser’s passengers, who claim they reported the drifting boat to staff. Passenger Jeff Gilligan was told his message was sent to the captain of the cruiser.

Birdwatcher Jeff Gilligan took a photo of the stricken boat from the Star Princess cruiser.

"It was very disturbing," he told reporters. "We asked other people, 'What do you think we should do?' Their reaction was: 'Well, you've done what you could do'. Whether something else could have been done, that's a bit frustrating to think about."

Under UN law it is compulsory to help vessels in distress, as long as it would not pose any danger to the ship. The master of the ship is required "to render assistance to any person found at sea in danger of being lost; to proceed with all possible speed to the rescue of persons in distress, if informed of their need of assistance, insofar as such action may reasonably be expected of him".

Princess Cruises said that it deeply regretted that one of its ships passed by the stranded boat, adding there had been a "breakdown in communication".