The terrifying moment a massive 18-foot shark passed within inches of a swimmer off the coast of Scotland has been captured on camera.
Ryan Leith, 48, had spent several days scouring the Shetland Islands looking for basking sharks before he spotted the elusive beast last Thursday.
But he couldn't have guessed quite how close an animal encounter he was in for.
"I had just about given up when I saw not one, but two sharks just off the coastline at Fladdabister," he said.
"They were feeding on the abundant plankton that blooms in the sea around Shetland during the summer.
"I stopped the boat and dropped the anchor. The shark seemed to be interested in the boat and swam towards it almost immediately.
"I took a lot of photos of it on the surface and then, as it seemed quite relaxed, I went over the side with my snorkelling gear on."
The moments that followed are caught on camera, showing the enormous creature passing within touching distance of Mr Leith. We also see the shark's enormous jaws open, ready to catch its lunch.
Mr Leith, a port controller for Lerwick Port Authority, estimated it was 18ft long.
"I waited close to the boat and filmed the shark with my GoPro as it passed by," he said.
"It was great to be in the water with such a large and powerful animal. The plankton it was feeding on limited the underwater visibility so it would only appear out of the gloom when it was a few metres away from me. It was quite exciting."
The basking shark is the second-largest extant shark in the world, after the whale shark.
A filter feeder, it's usually seen close to the surface with its huge jaws open, filtering out plankton, very small fish and invertebrates from the water.
Mr Leith said: "In the past — the 1950s and 60s — they were hunted around Shetland by Norwegian fishermen for their livers, which contain large amounts of oil.
"Thankfully now they are a protected species and their numbers are increasing.
"There have been a good number of basking sharks sightings around Shetland over the past few weeks which is great."
Despite the fierce reputation of sharks as a group, they rarely attack humans and basking sharks in particular are considered harmless.
Mr Leith documents his wildlife encounters on YouTube.