Oly Rush, 37, completed the 95.5km (59.3 mile) swim around Grand Cayman in 36 hours and 59 minutes.

Mr Rush, from Upton, Dorset, said the "absolutely brutal" challenge was "the hardest thing" he has completed.

Last August, he completed a 15-hour swim around the Isle of Wight to highlight marine pollution.

The plasterer was able to walk from the sea unaided but was taken in an ambulance to hospital after completing his latest feat.

1. "I got round but it was absolutely brutal, it was so, so difficult," he said.
2. "It took me to some very dark places and I literally wanted to ocean to swallow me up."
3. "I was never going to quit because I was so motivated by the environmental cause and what humans are doing to the planet, but it was the hardest thing I've ever done. 

Mr Rush said there were "no major incidents" during the swim, as he battled through difficult conditions that left him with a tongue so swollen he found drinking difficult.

He added: "It is too early to say what I'll do next but I'll continue to raise awareness about sea pollution and no doubt when I get home I'll be on beaches clearing them of plastics."