A Brisbane teenager has become the second-youngest person to swim the English Channel twice in one day, swimming 68 kilometres in 22 hours to make it happen.

Brianna Thompson, 17, lost a layer of her tongue and suffered from severe leg cramps and jellyfish stings in the swim from England to France and back — a feat of endurance only achieved by 20 others.

Her Sunshine Coast-based training partner, Sam Penny, said Brianna also had a swollen throat and faced the constant threat of hypothermia from swimming in the 16-degree Celsius water.

She finished the swim at Samphire Hoe, near the English town of Dover, about 11:35am on Wednesday.

In a statement, Ms Thompson said the worst part had been the “jellyfish stings and massive piles of floating seaweed”.

“When you are swimming for hours, these things give you a big fright,” she said.

“The jellyfish hurt for ages. They really aren’t fun.”

She said despite being back on dry land, she was too sore to sleep or sit in a chair.

“I’m in agony,” she said.

“It will be days before I can lift my arms above my head.”

Key points:

• Brianna Thompson took 22.5 hours to swim from England to France and back
• The 17-year-old says jellyfish stings were one of the worst parts of the endurance swim
• She cannot eat food for three days because the saltwater stripped a layer off her tongue

“People try every year to do the double crossing and can you believe a 17-year-old training on the Sunshine Coast absolutely smashed it?”

Source
Kathy Sundstrom and Robert Blackmore
ABC News