After winning three Olympic medals, Ederle turned her sights to a different challenge – swimming longer distances in open waters. Starting with a 22-mile swim from Manhattan's Battery Park to New Jersey's Sandy Hook in 1925, Ederle finished in a record-breaking seven hours and eleven minutes. Next, she had her eye set on swimming across the English Channel. In August 1925, Ederle entered the waters in her first attempt to accomplish her goal. However, after nine hours in the water and six miles from the English shore, her coach forced her to stop. Although that attempt fell short, Ederle wasn't going to give up that easily.

Reflecting on what hindered her previous try, Ederle designed her own goggles and swimsuit to increase her mobility. Donning her two-piece swimsuit and lathered in grease, Ederle entered the English Channel once again on August 6, 1926.

Prior to the swim, Ederle repeatedly asked for her team to trust her capabilities and allow her to complete the swim.

Not only did Ederle complete the swim, but she did so in 14 hours and 31 minutes, breaking the male record by nearly two hours.

In the early 20th century, the popular notion was that women were not as physically fit as men were. From her attire to athletic performance, Ederle's record-breaking swim turned that belief on its head. The original one-piece swimsuit Ederle swam in would quickly fill with water and chafe her skin, severely limiting her abilities. The two-piece suit Ederle designed as a replacement was very unconventional and many viewed it as too revealing. However, Ederle's performance was very inspirational for the many women who watched the swim broadcasted in their homes.

Stemming from her previous measles infection during childhood, Ederle began losing her hearing following her major swim. Retiring to her home place of New York City, Ederle spent her life teaching deaf children how to swim. At age 98, Ederle passed away on November 30, 2003, leaving a lasting legacy in women's sports.