Caleb Grace, from Beaconsfield Road in Wick, was chosen to be one of seven swimmers to fly the flag for Great Britain at the Special Olympics, an independent global event for athletes with intellectual disabilities.
The 19-year-old trainee bricklayer will be taking the second flight of his life in March next year to go to Abu Dhabi in the United Arab Emirates, where he will be competing in the men's 100 metres breaststroke, the 200 metres freestyle and the 200 metres individual medley as a category S14 swimmer.
He needs to raise £2,500 to get there - and has set up a JustGiving page and will be doing a sponsored swim at Littlehampton Swimming and Sports Centre in Sea Road on Friday, May 20, at 6pm. Click here to donate.When he opened the email saying he had made the cut, it took a while to sink in, he said: "When I first learned of it, I was amazed. I was like, 'are you sure? I want another email confirming it!'"
He first started swimming aged 11, when his PE teacher Claire Moyle at Oak Grove College in Durrington spotted his potential and put him in contact with the Sussex Squids, a disabled swimming group.
Caleb flourished and moved to the Littlehampton Swimming Club at 13, where he became their first disabled swimmer and his training intensified, eventually swimming seven days a week at the Sea Road leisure centre.
Claire, who is also head coach for the Special Olympics' Worthing branch, which covers West Sussex, said: "It is really good to see him develop in confidence. Once he knew he was good at something, his attitude to life changed and he became more determined in all parts of his life."
Being autistic means it takes Caleb longer to learn swimming strategies and training techniques, and at first the noise and bustle of the pool was daunting to him: but he took to it like a fish to water.
Caleb said: "It is really helpful going against people who are able bodied, because they will always be faster than me, so when I go against other disabled people I have an advantage."
This strategy has converted into silverware during his competitive career, with dozens of medals in a variety of events. His medal tally includes two golds at the national Special Olympics in Bath in 2013 and a gold and two silvers at the Sheffield national Special Olympics last year, where his 18-year-old brother Oliver, a sprinter and long-jumper, also won four bronze medals.
At Abu Dhabi, the medal contender will be up against swimmers from many of the 172 countries that take part. But with eight training days with Team GB coming up, the athlete can hone his skills in the hunt for the gold.
His mother Tansley Grace will be cheering him on from the sidelines. She said: "I will be a bit tearful when he is in his Team GB kit. I will say, 'that's my boy!'"
When asked which swimming greats he looked up to, Caleb's competitive streak shone through. He said: "I don't admire them; I want to beat them."