A North Sea oil worker has captured stunning footage of the moment a pod of orcas surrounded his vessel.
Graeme Hately is the chief officer on board an Emergency Response and Rescue Vessel, which looks after oil platforms.
His boat was immersed in fog on Friday night about 100 nautical miles north of Lerwick when the haze suddenly lifted and he could see orcas swimming around him.
He said: “We were completely surrounded by fog for most of the day. As the fog was lifting, Albert, my watch-keeper said he could see some orcas.
“As the fog was lifting we could see more and more off into the distance as well as around the ship.
“There were about 20 altogether, with some males at the back who appeared to be driving something, probably herring, towards the rest who were thrashing with their tails and flipping out of the water.
“We get to see this a couple of times a year but it is always exciting.”
Graeme documents his life at sea through his Bigwavemaster1 YouTube channel.
His watch-keeper Albert Ritchie comes from Whitehills, while Graeme himself lives in Nottinghamshire.
Orcas have been spotted more and more frequently around the Shetland Islands in recent years, due in part to increased communication of social media alerting people of the best places to spot them, typically during the spring and summer months.
Although Mr Hately recorded his sighting far out to sea, the charismatic animals can also be seen from dry land.
They been spotted swimming in the waters of Lerwick Harbour, around Levenwick, near Sandwick, off the South Mainland and in a number of other locations.
The pursuit of orca-spotting has been argued to be a major boon to Shetland’s tourism industry, which benefits from visitors coming to the islands for wildlife and bird-watching.