U.S. swimmer Nyad plays a trumpet before attempting to swim to Florida from Havana.
U.S. swimmer Nyad plays a trumpet before attempting to swim to Florida from Havana.The 61-year-old plunged into the Straits of Florida at dusk on Sunday to begin what she hopes will be a world record 103-mile (168 km) swim from Cuba to Florida. The same swim was completed successfully by Australian Susan Maroney in May 1997. But Nyad's claim to a world record will be that unlike Maroney, she is doing it without a shark cage in the strait's warm, shark-infested waters. Nyad will be protected by a surrounding electrical field and by divers who will watch for sharks and drive them away if they get too close. REUTERS

World record-holding swimmer Diana Nyad entered the water off of Havana's Marina Hemingway at 7:45 p.m. ET on Sunday. She got her starting wish- good weather and a calm sea. She is swimming from Havana to the United States in an effort to promote better relations between the two countries.

Nyad, 61, also wants to prove that there is life and fun after 60. She has no qualms about her age affecting her swim game.

"I am a better athlete today than I was at 29," the champion swimmer told CNN, the only network accompanying her on the swim.

She declined to use a shark cage for the trek.

"I don't want to have that asterisk next to my name," she told "The Today Show."

Still, Nyad will not be alone. She will be accompanied by five yachts and four kayaks. She will have a 45-person support team that includes trained shark divers. Nyad will reportedly tread water every 45 minutes for a rehydrating break and have a bite to eat every 90 minutes. In order to set a record, Nyad cannot touch a boat until she reaches land.

Nyad became a serious swimmer in the seventh grade. She was 20 years old when she completed her first competitive marathon swim across Lake Ontario. She last swam competitively at the age of 30, when she swam from North Bimini Island in the Bahamas to Juno Beach in Florida. She did not use a shark cage then, either.

She was inducted into the National Women's Sports Hall of Fame in 1986. She was inducted into the International Swimming Hall of Fame in 2003.

"It doesn't have to be a big moment," she told NBC about her Cuba swim. "It just means be engaged in your life. Don't let it go by. We all have one life and it's a one-way street."