Ross Edgley, a 39-year-old endurance swimmer from Cheshire, has become the first person to swim completely around Iceland, finishing a coast-to-coast circumnavigation of roughly 1,000 miles (1,609 km).
He returned to Reykjavík on Monday afternoon to complete the challenge and was welcomed at the finish by a viking horn and champagne.
Edgley began the expedition in Reykjavík on 17 May. He followed a pattern of swimming for six hours and then resting for six hours aboard a dedicated support yacht throughout the journey, which took him nearly four months.
The route exposed him to cold water temperatures, marine life and rough seas. He documented harsh physical effects from the environment, reporting severe wetsuit chafing and that parts of his tongue were damaged by prolonged saltwater exposure. Before the swim he said he had to consume more than 10,000 calories a day to add as much "insulation" as possible and reduce the risk of hypothermia.
Edgley has spoken of being inspired by actor Chris Hemsworth. He has previously joked that the challenge would be "the closest thing yet to swimming around Asgard" -- a reference to the mythical Norse realm associated with the character Hemsworth plays in the Marvel films.
In addition to the physical feat, Edgley described the project as having a research purpose. He wrote on social media that it "wasn't just a swim" but also a "scientific expedition for ocean conservation".
As part of this work, he collected daily environmental DNA (eDNA) samples from the waters around Iceland to contribute to data on biodiversity and the presence of microplastics. The research was carried out in collaboration with several scientific organisations, including the University of Iceland.