Marathon swimmer Diana Nyad was making headway through the Florida Straits despite some physical complaints Monday, about one-third of the way into her attempt to log a record swim at age 61.
While Nyad was pausing only briefly for nourishment and is not allowed to touch the support boat, her team kept fans and well-wishers up to date through social media.
"Diana is swimming strongly. The swells have subsided," said someone posting on her Twitter account in the morning.
"We're very pleased with her progress," her Facebook page read.
Both social media accounts said in the afternoon that she was experiencing some shoulder problems and asthma but doing well.
Nyad is trying to accomplish at 61 years old what she failed to do at 28: swim an estimated 60 hours covering 103 miles from Havana to Key West. This time she is attempting the swim without a shark cage, relying instead on an electrical field from equipment towed by kayakers to keep sharks at bay.
If successful, Nyad would break her own record of 102.5 miles for a cageless, open-sea swim, set in 1979 when she swam from the Bahamas to Florida.
She will have to overcome fatigue and potential debilitating problems like nausea and chafing from the salty water. She said she was bringing along 25 pairs of goggles -- including light blue for nighttime vision and darker ones for daylight -- and any suit changes will happen right there in the water.
The conditions, which thwarted her previous attempt at the Cuba-US swim in 1978, seem to be in her favor.
The sea was flat as a "silver platter" around sunset Sunday when she began her journey.
"The adrenaline's flowing now," she said as she looked at the water from a Havana jetty. " I don't believe much in destiny, but you have to take what you can get, and this is what I dreamed of: a silver platter."
Monday dawned much the same in Havana -- calm waters, muggy, with just a hint of a breeze. The favorable conditions are predicted to last until Thursday.
She said she hopes her feat, if successful, will inspire people to live vigorously during their golden years.
"I also want it to be a moment for thousands, and I dare say millions of people my age, who are going to look and say, '60!' " she said Sunday at a news conference. "The joke is 60 is the new 40, and it's true. We are a younger generation than the 60 that went before us."
She called the attempt a "symbolic moment" for increasing understanding between the United States and Cuba, two nations torn by five decades of animosity and mistrust.
"I'm under no delusion that my swim is going to make any new political ramifications," she added. "But it is a human moment between the two countries."
She promised to come back soon for a post-swim party. Whether that will be a victory bash remains to be seen, but a quote by Nyad posted to her Twitter account suggests she is determined to go all the way.
"If I go unconscious, that's one thing," it read. "But no one is going to make me get out of the water, that will never happen."
Nyad first had a go at this crossing as a 28-year-old back in 1978, when she swam inside a steel shark cage for about 42 hours before sea currents hammering her off course put an end to that attempt.
She said the aborted attempt stuck with her all these years, and upon turning 60, she started thinking about a comeback.