Sarah Thomas completed her treatment for breast cancer just last year. Now the 37-year-old from Colorado has another reason to celebrate: She just became the first person to swim across the English Channel, which separates England from France, four times nonstop, reports the BBC. 

To complete her journey, which began on September 15, Thomas contended with jellyfish, strong tides and saltwater (which she says hurt her throat) for more than 54 hours. An experienced swimmer who was diagnosed with breast cancer less than two years ago, she dedicated her swim to other survivors.

“There was a lot of people on the beach to meet me and wish me well, and it was really nice of them, but I feel just mostly stunned,” Thomas told the BBC. “I just can’t believe that we did it.”

Although her swim was supposed to be about 80 miles, strong tides caused her to swim over 130 miles. 

“I’ve been waiting for this swim for over two years now and have fought hard to get here,” Thomas wrote in a Facebook post prior to setting off on her challenge. In the same post, she  dedicated her swim to “all the survivors out there,” according to NBC News. “Am I 100%? No. But I’m the best that I can be right now, with what I’ve been through, with more fire and fight than ever.”

A boat equipped with GPS systems and several computers to monitor wind, tides and currents accompanied Thomas during her swim. Her husband, mother and other swimmers were also there for support throughout the excursion.

To refuel, she took breaks every 30 to 60 minutes while swimming to have a protein drink mixed with electrolytes and some caffeine. She also ate her favorite snack, M&Ms.

On September 18, Thomas wrote about her experience in a lengthy Facebook post, which detailed preparations for her swim, the swim itself and a current update. She is currently recovering and believes it may be a while before she gets back in the water.

“A year ago, I didn’t know if this swim would still be possible for me,” she wrote. “But I didn’t let go of my dream and gave it everything I had.”

For more stories from cancer survivors, visit our Cancer Health Stories.