Update 22 Feb 2021: Added that Webb attempted to cross the Niagara River below the falls, not above them (thanks to information provided by a well-informed reader).
In the summer of 1976, Diana Nyad flies to England…
…happily accompanied by my two closest friends…and by an American film crew of seven. We were off to make, assist, and record history. I was attempting to become the first woman to complete the double crossing of the English Channel. (Other Shores, 1978, p. 121)
Nyad passes some time during the flight reading the Channel Swimming Association (CSA) handbook. She paraphrases:
Who knows the story of Captain Matthew Webb…? Webb was the first to swim across…. Some weeks later Webb tried to cross the Niagara River four hundred meters above the falls; he is buried at the bottom. (p. 122)
The way Nyad describes it, Webb would barely have time to dry off before steaming across the Atlantic. Once in the U.S., he’d have to hightail it for Niagara and jump right back in the water.