Subscribe | UPI Odd Newsletter Subscribe June 8 (UPI) -- A swimmer known as the "eco mermaid" broke a Guinness World Record by taking a 26.22-mile swim in the ocean while wearing a monofin. Merle Liivand, a swimmer and conservationist known as the "eco mermaid" due to her monofin swimming skills, spent 11 hours and 54 minutes swimming off the coast of Miami Beach, Fla., to break her own record for farthest swim with a monofin. Advertisement Liivand, who is originally from Estonia and relocated to Florida 11 years ago, said she felt her previous Guinness World Record in April 2021 was hampered by less-than-ideal marine conditions, leading her to break her own record of 18.6 miles on May 7 of this year. "I was born with auto-immune health problems, and I started swimming because my lungs collapsed," Liivand told Guinness World Records. "Today, my intention is to fight for Mother Earth's lungs." She said her latest monofin swim was not without its difficulties. "I got stung by jellyfish and kept telling myself that it was not the time to cry," Liivand said. "The moments where I was feeling down, I had to remind myself that I'm a tool between the ocean and humans and I want my message to be heard." Advertisement Liivand said she also had some positive wildlife interactions during her swim, including some dolphins and a mother manatee with a baby. Read More Colorado police: 'Stop trying to take selfies' with loose moose Display featuring more than 70,000 pounds of bananas breaks world record Loose bearded dragon in Louisiana becomes police officer's 'new buddy'