Diana Nyad successfully completed, on her fifth attempt, her 103-mile swim from Cuba to the US. News reports emphasized that she was the first person to do so without a shark cage. David Shiffman, who studies sharks, says that the repeated mentioning of that statement may have given the impression that sharks pose a particularly acute danger when they do not. Jellyfish were more likely to have derailed her, as The Onion notes.
Shiffman explains a possible reason the cage-free emphasis.
The shark cages used by distance swimmers are very different from the shark cages used for recreational scuba diving with great whites. They are large and dragged behind a boat, and they give what some say is an unfair advantage to swimmers by reducing drag. In 1997, Susie Maroney became the first woman to swim from Cuba to Florida, but she used a shark cage. The frequent use of “without a shark cage” in media coverage could simply be meant to specify which record Diana Nyad technically earned, but we rarely see such attention to technicalities. The phrasing is likely meant to convey the supposed danger of swimming with sharks more than the specific record she earned.
His article gives some interesting information on sharks and their behaviors.
Of course, doing this at her age (64) is a major achievement for Nyad. Although it would never occur to me to attempt such feats of endurance and their appeal eludes me completely, one has to admire the sheer determination that drives people like Nyad to try such things.