Crew member Ivan Doychev, 40, became separated from his boat on May 3, 2017, and rescue crews – including two helicopters and four commercial vehicles – were unable to locate him.
The company he was diving for, Orkney Dived Scallops, were found not to have accurately recorded the dive, and did not ensure that all divers had the appropriate medical certificates.
They also failed to provide necessary equipment to its crew, including personal location beacons or a suitable lifeline.
Another incident in March of the same year saw the company fail to have enough qualified crew to carry out a safe dive.
They also did not ensure the health and safety of a 17-year-old crew member during this dive.
The company plead guilty last month to three charges at Kirkwall Sheriff Court and this week was fined £15,000.
Head of the Crown Office and Procurator Fiscal Service Health and Safety Investigation Unit Alistair Duncan said:
“By failing to ensure their vessels were crewed by properly qualified divers, and by not providing appropriate safety equipment, Orkney Dived Scallops put their employees at unacceptable risk.
“This resulted in a prolonged ordeal for one crew member, who was stranded at sea for eleven hours.
“This prosecution should serve as a reminder to other fishing companies of their responsibilities to their workers.”