A workman suffered multiple fractures when he reportedly fell 30ft at a harbour.
Northern Constabulary said the man, who was working on board a ship docked at Wick Harbour, in Caithness, fell onto the boat's decking at about 6.30pm on Monday.
He sustained broken bones but police said his injuries are not life threatening.
The Press and Journal newspaper reported that the man was unloading parts for wind turbines when the accident happened.
A police spokesman said: "Northern Constabulary are carrying out inquiries into an accident that took place at Wick Harbour on Monday January 7 about 6.30pm.
"The Health and Safety Executive have also been involved in the inquiry and at this time investigations are still ongoing."