Nyad began seriously competing in swimming competitions in junior high and held Olympic hopes for the summer of 1968 until a serious heart infection put an end to her dreams that year. Nyad later was encouraged to try marathon swimming whereby the has excelled beyond records and recently even belief.
1974: In June 1974, Nyad set a women's record of 8 hours, 11 minutes in the 22-mile (35 km) Bay of Naples race.
- 1975: At age 26, Nyad made national headlines by swimming 28 miles (45 km) around the island of Manhattan (New York City) in just under 8 hours (7 hours 57 minutes.) An account of her swim, published the next day, stated Nyad was 5 feet 6 inches (1.68 m) tall (1.7 m) and weighed 128 pounds (58 kg).
- 1978: At age 28 she first attempted to swim from Havana, Cuba to Key West, one year after the Kennedy-era travel restrictions were lifted. Diving into the ocean at 2PM on Sunday August 13 from Ortegosa Beach (50 miles; 80 km west of Havana), she swam inside a 20-by-40-foot (6.1 m × 12.2 m) steel shark cage for nearly 42 hours, before team doctors removed her during the 7 o'clock hour on the morning of Tuesday August 15 due to strong Westerly winds and 8-foot (2.4 m) swells that were slamming her against the cage and pushing her off-course towards Texas. She had covered about 76 miles (122 km), but not in a straight line.
- 1979: In what was to be her last "competitive" swim on her 30th birthday (August 21–22, 1979), she set a world record for distance swimming (both men and women) over open water by swimming 102 miles (164 km) from North Bimini Island, Bahamas, to Juno Beach, Florida (without the use of protective shark cage). Thanks to favorable winds and a following sea she averaged 3.7 miles per hour (6.0 kilometres per hour) and completed the swim in 27 and one-half hours.
In 2013 at the tender age of 63, Diana Nyad swam from Havana, Cuba to Florida, a distance of about 110 miles (180 km), accompanied by a 35-person support team, swimming without a shark cage but protected from jellyfish by a silicone mask, a full bodysuit, gloves and booties. Before reaching Florida, Nyad broke Penny Palfrey's 2012 distance record for the Cuba to Florida swim,[discuss] putting Nyad closer to Key West than anyone swimming without a shark cage. At approximately 1:55 pm EDT on September 2, 2013, Nyad reached the beach in Key West, about 53 hours after she began her journey.
Diana Nyad has showed us woman can be done differently at ANY age!