Chloe McCardel yesterday became the first person to swim almost 80 miles (129km) unassisted in open water during a 42½-hour crossing from Eleuthera in the Bahamas to Nassau, according to her support team.

In a statement her team said that the swim met international rules set by the Marathon Swimmers Federation and if her achievement is ratified officially, the 29-year-old Australian will have completed "the longest open-water solo, continuous, unassisted marathon swim in history".

Wearing only a regulation bathing suit, swimming cap and goggles, McCardel was greeted by supporters in Nassau, alongside her husband, Paul McQueeney, and crew. "I know she will take some time to recover from this massive achievement which she has spent her entire career preparing for," said McQueeney. "She is elated at setting this record and is a very, very proud Australian."

McCardel has completed seven solo crossings of the English Channel, an achievement which two non-stop double crossings. In June last year, she was forced to abandon an attempt to become the first person to swim from Cuba to Florida without a shark cage after she encountered a stinging swarm of jellyfish. McCardel was pulled from the water 11 hours into that 103-mile marathon swim.

A few months later the 64-year-old American long-distance swimmer, Diana Nyad, completed the Cuba crossing successfully in 53 hours. She was equipped with a protective silicone mask as well as a body suit to better protect her from box jellyfish which had forced her to end a previous attempt to make the crossing. A team of ocean kayakers and divers accompanied Nyad on her ­journey dragging an electronic device in the water which emitted an electrical current to repel sharks.