Cieran Kelso, 8, lost both his legs below the knee to meningitis when he was just 13 months old.
His dad, Gary, and stepmother, Gemma, were determined that Cieran would still lead an active life.
Gary raised enough money to buy his son prosthetic flippers so Cieran could go swimming with his friends.
"We want Cieran to see that even though his legs were taken away by his meningitis he can still follow his dreams and be like his friends, just sometimes we have to make slight adaptations to aid him along the way," Gemma told the Daily Mail.
This summer, the young boy travelled from his home in England to the Clearwater Marine Aquarium in Florida to swim with Winter, the dolphin with a prosthetic tail who inspired him.
Winter starred in the family film "Dolphin Tale."
"His first words when he saw the film was, 'Winter's disabled just like me,'" Gary told the Daily Mail. "There are some pretty raw feelings that go into seeing Cieran swim with the dolphin."
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Gary and Gemma kept the trip to see the dolphin a secret from their son until the family was on their way to Florida.
While they knew Cieran would be able to meet Winter, they didn't know that he'd be able to get into the tank with her.
"I think he was in shock when he found out he could swim with her," Gemma said. "He thought he would only be able to meet her — he was just the second visitor to be allowed to swim with her as well."
Winter and Cieran, accompanied by a trainer, swam together for more than an hour. Cieran's little sister, 5-year-old Layla-Eve, and Winter's "sister" Hope also joined them in the tank at one point.
"It was greater than great," Cieran said of the swim.
"The feeling was great to be swimming, just emotional to be swimming with a dolphin," said Cieran. "I love dolphins, but the best dolphin I've ever loved is Winter."
The trip of a lifetime left quite the impression on the young boy.
"Since we got back he is calmer and more content in himself. His dream job is now to go back and look after Winter — he no longer wants to be a train driver!" Gemma said.