Video report by ITV News Correspondent Peter Smith
A British sportsman has broken the world record for the longest staged sea swim - but he is only half way to achieving his goal of swimming the coast of the British Isles.
So far Ross Edgley has spent 74 gruelling days at sea, but has another 900 miles to go before he can become the first man ever to swim the circumference of the UK.
He spends a total of 12 hours every day submerged in sea water and in that time swims the equivalent of the English Channel.
He has a support boat, sponsored by Red Bull, following him on the route, but only gets out the water in order to sleep, and never sets foot on solid ground.
ITV News Correspondent Peter Smith was forced to take a dip himself and swim over to Ross in order to ask him why he's doing it.
"The why, as to why I'm doing this, has probably changed quite a few times, but the scenery is stunning," he said.
Swimming for such a long distance every day takes up around 15,000 calories of energy - that means he is eating the equivalent of 18 portions of fish and chips every 24 hours.
Despite his skin struggling to adapt to long periods submerged, giving him what he describes as "trench foot", the most difficult obstacle to overcome has been sting of jelly fish.
Ross has been keeping a video diary of his developing wounds and some of the images are truly shocking.
While many would have given up when faced with such excruciating wounds, Ross has come up with an important coping technique.
"I swim with a smile because if you swim with a smile, then, not to get too deep, but the psychology and sports science of it, it can affect everything including your immune system," he said.
But he added that swimming with a smile can get "weird" when it is being done for 12 hours a day.