KEY WEST, Fla. — Any day now, Diana Nyad will set out to do something no athlete has ever done: swim all day and all night, then all day and all night, then all day again.

She will swim about 60 hours in the churning sea, 103 miles across the Straits of Florida from Cuba to Key West. Every hour and a half, she will stop to tread water for a few minutes as she swallows a liquid mixture of predigested protein and eats an occasional bit of banana or dollop of peanut butter. She will most likely hallucinate and endure the stings of countless jellyfish. Along the way, sea salt will swell her tongue to cartoonish proportions and rub her skin raw.

“She is up against the most outlandish, outrageous, unbelievable physical endurance activity of, certainly, my lifetime,” said Steven Munatones, a champion open-water swimmer who runs the organization Open Water Sourceand will serve as an independent observer during Ms. Nyad’s swim. “I can’t imagine being in the ocean for 60 hours. I can’t imagine doing anything for 60 hours. It is inconceivable. It simply is.”

“Especially,” he added, “at her age.”

Her age is 61. Ms. Nyad attempted this swim once before, unsuccessfully, in 1978 at the age of 28. She swam inside a shark cage for 41 hours 49 minutes until the raucous weather and powerful current pushed her far off course and she was forced to give up. She had traveled only 50 miles. (One year later, she swam 102 miles from Bimini, in the Bahamas, to Jupiter, Fla., without a shark cage. She still holds the record for the world’s longest ocean swim.)

This time, armed with better technology and a battered but tough body, she is certain she will make it. “Physically, I am much stronger than I was before, although I was faster in my 20s,” said Ms. Nyad, who looks sturdy enough to defy a linebacker. “I feel strong, powerful, and endurance-wise, I’m fit.”

Dr. Michael J. Joyner, a professor of anesthesiology and exercise research at the Mayo Clinic, agrees that older athletes, particularly superb ones, do well in endurance sports, because experience and training can offset the need for speed.

At 52, Jeannie Longo still ranks as a top competitive cyclist. Gordie Howe played hockey into his 50s, and Jack LaLanne was 60 when he swam from Alcatraz Island to Fisherman’s Wharf, in San Francisco, for a second time, handcuffed, shackled and towing a 1,000-pound boat. Swimming is particularly technique-driven, which will help Ms. Nyad tremendously.

“There are a ton of examples of people in their late 50s and early 60s doing all sorts of wild things,” Dr. Joyner said. “If the logistics work out, barring bad storms or currents, it is doable. It’s not a sure thing. But it wouldn’t be a sure thing if it were Michael Phelps.”

If Ms. Nyad makes it from Cuba to Key West, she will be the first person to have done so without a shark cage. In 1997, an Australian woman completed the swim inside a shark cage. But with a boat pulling the cage, the swim is easier and faster; the woman completed it in less than 24 hours.

“I’m in uncharted territory,” Ms. Nyad said.

This time around, Ms. Nyad, an accomplished marathon swimmer and sportscaster, is taking no chances. She has trained harder — for a year and a half — and changed her regimen. Rather than swim every day, she swims every other day. Last year, she completed a 24-hour swim in Mexico.

To help her succeed, she has organized an armada of people — 22 in all — to serve as her support team. All of them will travel to Cuba, visas in hand, and will try to arrive within three days of her swim. (An effort last year was called off because of visa difficulties.)

“That’s the part that really interests me about Diana,” Mr. Munatones said. “It’s not just the swimming part. There are people who can swim this. But they don’t have the organizational, political and passionate oratorical skills she has.”

She also has technology on her side: satellites, global positioning systems, advanced navigation software, even shark shields, none of which were available in 1978. The cost for all this is $500,000. She has raised money and depleted her own bank account, but she is still $150,000 short. Ms. Nyad, a commentator for the Los Angeles-based public radio station KCRW, shrugs it off.

“If I wind up $150,000 in debt, I won’t lose sleep over it,” she said.

At the moment, four experts are looking seven days ahead to pinpoint the ideal weather for her to travel to Cuba and wade into the ocean: a satellite oceanographer and meteorologist trained in the vagaries of the Gulf Stream; another meteorologist who works for CNN; and two officials at NOAA, the National Oceanic and Atmospheric Administration. They are all hoping for the beginning of a low-pressure system that could create the doldrums, a waveless sea, for a few days.

To stay on course, her seasoned navigator, David Marchand, relies on his laptop, with navigational tools so precise they can alert him immediately if she drifts off course. Any major deviation would destroy her chances.

“Day 1 and Day 2, we want flat calm,” said Mr. Marchand. “By Day 3, well, it’s hard to get three days of flat calm. But even in a flat sea, you can get a squall — rain, thunder for 15 minutes to an hour, and then calm again. You can’t dodge them. And it’s almost an impossible swim as it is. You have to keep in a straight line.”

Two men in kayaks will follow Ms. Nyad’s every stroke. They will hold a shark shield — neoprene rods that emit electrical waves to zap sharks that come too close. The waters between Cuba and Key West are a notorious shark playground. But the shield is not foolproof. Just in case it fails, as it did last year in the Caribbean when another woman was on a marathon swim, four shark divers with spears will be onboard, ready to jump.

Some contraptions are decidedly low-tech. As Ms. Nyad swam recently off the shore of Key West at a pace of two miles an hour for nine hours, she followed a white streamer beneath her, like a line in a pool. Keeping her eye on the boat had been difficult, and she would often veer off course. Crew members found that if they attached a streamer to a long pole and dropped it into the ocean, she could see it underwater. Problem solved.

Another advantage Ms. Nyad has, three decades after her first attempt to cross the straits, is the emphasis on sports nutrition. In 1978, Gatorade stood mostly alone in the field, and even then it was a niche drink. Now Ms. Nyad has her predigested proteins to drink and gel blocks of electrolytes to suck on to keep her calorie intake high and her body hydrated and balanced.

Still, her doctor worries about hydration, starvation and keeping her body warm in the water. The ocean must be at least 86 degrees, which sounds warm unless a person is in it for 60 hours.

“The big concerns are, can she stay awake, focused and hydrated,” said her physician for the swim, Dr. Michael S. Broder, an associate clinical professor at the University of California, Los Angeles, School of Medicine. Some days her long swims have made her sick and other days they have not. “Because nobody else has ever done this, it’s not clear what causes all the things she has experienced,” Dr. Broder said.

The mental game, too, could doom her. Conditions in the ocean are nothing if not hostile. There will be no gorgeous sunset she can watch to buck up her spirits, as there would be if she were running or cycling. No music playing or conversation to distract her from her pain.

Instead, Ms. Nyad sings songs — Neil Young, the Beatles, Janis Joplin — seemingly thousands of times a day to ward off monotony and stay in the moment. She likes songs that have a cadence to match her stroke, like “Ticket to Ride.”

“That’s 7,929,” she said, announcing a typical tally for that song. “And here we go again: ‘I think I’m going to be sad. I think it’s today, yeah.’ ”

Ms. Nyad added, “Swimming is the ultimate form of sensory deprivation,” a fact that carries a particularly harsh sting for a speed talker like her. “You are left alone with your thoughts in a much more severe way.”

But why go through this agony again?

Ms. Nyad pinned the reason on her gallop toward 60; it unsettled her greatly. She needed a fresh, powerful target to stir up her energy and ambition. And although she had given up swimming abruptly in 1979, a casualty of burnout, her mind seized on her unsuccessful swim to Key West.

“This is what I need to remedy my malaise,” Ms. Nyad said. “I need commitment to take over. That level of commitment has such a high. There is no thinking about regrets or what will I do with the rest of my life. I’m immersed in the everyday, full tilt. It’s so energizing.”

Ms. Nyad no longer swims in anger, as she did in her youth, when she was working through the sexual abuse she said she suffered as a teenager. Now, she said, she swims in awe of the world around her.

There is ego involved, of course. But her swim has helped her turn a corner, she said, adding that she hopes it will empower others her age.

“I hope a couple will say, ‘I want to live life like that at this age,’ ” Ms. Nyad said. “I want the candle to burn bright. We have changed a lot. Our parents’ generation, at 60, they considered that old age. I’m in the middle of middle age.”

This article has been revised to reflect the following correction:

Correction: July 20, 2011

An article on Tuesday about Diana Nyad, who at age 61 is preparing to swim from Cuba to Florida, misstated her professional role. She is a commentator for the Los Angeles-based public radio station KCRW; she does not work for National Public Radio.

Recent Articles

Date Title
7/29/11 U.S. should not retreat from the hemisphere
By Bill Richardson, The Miami Herald
7/28/11 Castro Offers a Wave at Cuban Fete, but, Again, No Speech
By Damien Cave, The New York Times
7/28/11 Tampa airport to begin weekly charters to Cuba
By Mimi Whitefield, The Miami Herald
7/28/11 Kerry lifts hold on cash promoting Cuba democracy
Associated Press
7/28/11 Dutch bank ING may face U.S. sanctions
By Juan Tamayo, The Miami Herald
7/28/11 The Last Pilgrims to Havana
By Yoani Sanchez, Foreign Policy
7/27/11 A Breath of Freedom Suffocated
Christopher Sabatini, The Huffington Post
7/27/11 Cuba VP: Gov’t pushing ahead with economic reforms but not enough headway
By Juan Tamayo, The Miami Herald
7/27/11 The door opens for more Cuba travel
By Mimi Whitefield, The Miami Herald
7/26/11 Cuban court hears appeal of jailed U.S. subcontractor Gross
By Juan Tamayo, Miami Herald
7/26/11 Mass honors Cuban archbishop
By Daniel Roth, The Miami Herald
7/25/11 Chávez Returns, Saying Cancerous Cells Not Found
By Alexi Barrionuevo, The New York Times
7/25/11 Cuban archbishop a freedom-fighter with one weapon
By Myriam Marquez, The Miami Herald
7/25/11 Jailed American makes final court appeal in Cuba
By Paul Haven, Associated Press
7/25/11 A Cuban housing market? Gov't is lifting a taboo
By Peter Orsi, The Miami Herald
7/22/11 Cuban government hijacks the mega-music Rotilla Festival
Roots of Hope
7/22/11 Ros-Lehtinen urges constituents to post photos of Cuban human rights abuses
By Juan Tamayo, The Miami Herald
7/22/11 Mixed messages as Cuban high court hears imprisoned American’s final appeal
Associated Press
7/22/11 Diaz-Balart seeks to revive Bush-era Cuba travel
Associated Press
7/21/11 Issue #2: Current Situation & Future of the Relationship Between Cuba & the United States Files
Miriam Leiva, From the Island
7/21/11 Congresswoman says curbs on travel to Cuba ignored
By Stephen Levy, The Washington Times
7/21/11 Ping Pong Diplomacy: Will Cuba Catch Up?
By Christopher Sabatini, The Miami Herald
7/21/11 Cuba says 900 agricultural experts advising Venezuelan farmers
Associated Press
7/21/11 Businesses see potential profits in Tampa-to-Cuba flights
By Jose Girona, Tampa Tribune
7/20/11 Cuba’s shadow economy sees some daylight
By Paul Haven, the Associated Press
7/20/11 Could Catholic leader usher in a new Cuba?
By Mark Pinsky, USA Today
7/20/11 Lacking a wholesale market, Cuba cuts prices for bulk purchases to aid private workers
Associated Press
7/20/11 Current Record
7/18/11 Blogger: Cubans thirsty yet wary
By Sarah Moreno, The Miami Herald
7/18/11 Hugo Chavez Cancer: Venezuelan President Delegates Powers To Vice President Elias Jaua
Huffington Post
7/18/11 Chávez Puts His Trust in Castro for Care
By Alexi Barrionuevo, The New York Times
7/15/11 Time for Reflection and Prudence
Oscar Espinosa Chepe, Reconciliacion Cubana
7/15/11 Dems, State Dept near resolution on Cuba money
By Donna Cassata and Desmond Butler, Associated Press
7/14/11 Venezuela’s Chavez says he expects to undergo chemotherapy or radiation treatment
Associated Press
7/14/11 Congressional Amendment Threatens Cuban Families
Yoani Sanchez, Huffington Post
7/13/11 The Cuban Grapevine
By James Scudmore, More Intelligent Life Magazine
7/13/11 Obama Administration threatens veto over Diaz-Balart Ammendment
Executive Office of the President
7/13/11 My Reasons for the Bridge
Yoani Sanchez, Generación Y
7/13/11 Mother of Cuban dissident tells US lawmakers about son's death
By James Rosen, The Miami Herald
7/12/11 Chavez says cancer fight 'my longest walk'
By Christopher Toothaker, Associated Press
7/12/11 Cuba banker says state has lent ‘millions’ to more than 13,000 farmers under ag initiative
Associated Press
7/11/11 Cuba academic who wrote blistering anti-corruption essay says expulsion from Party overturned
Associated Press
7/11/11 Life at GTMO after fleeing Castro's Cuba
By Anthony Welsch, WBIR News
7/11/11 Transgender activist resigns after clash with Castro daughter
By Juan Tamayo, The Miami Herald
7/8/11 Cuba says detained US contractor Alan Gross’ appeal to be heard July 22
Associated Press
7/8/11 Cuba says 16 percent of islanders have access to some kind of online service
Associated Press
7/8/11 Cuban cellphones hit 1 million, Net access lags
By Marc Frank, Reuters
7/7/11 If Hugo goes
The Economist
7/7/11 DNC boss, president at odds on Cuba policy
By Mike Lillis, The HIll
7/7/11 Spain may change tone on Latin America
By Andres Oppenheimer, The Miami Herald
7/6/11 Human rights group says abuses in Cuba are growing
By Juan Tamayo, The Miami Herald
7/6/11 Cuba Travel Restrictions in the Spotlight in Brooklyn and Beyond
By Matthew Aho, Americas Quarterly
7/6/11 Our secret deportation list: It may be legal, but is it right?
By Jackie Bueno Sousa, The Miami Herald
7/6/11 In Cuba, the Voice of a Blog Generation
By Larry Rohter, The New York Times
7/5/11 Insufficient and Unclear Guidelines
Oscar Espinosa Chepe, From the Island
7/5/11 Cuba’s economic czar heads new generation of leaders
By Andrea Rodriguez, Associated Press
7/5/11 Former US presidential candidate McGovern leaving Cuba without meeting friend Fidel Castro
Associated Press
7/4/11 Ballet Points to U.S.-Cuba: Friendship Is Not an "Impossible Dream!"
By Noel Erwin Hentschel, The Huffington Post
7/4/11 Cuban economic reform aims to bring a world of secret businesses into the light
Associated Press
7/4/11 TwittHab: Cuban tweeters meet face to face, celebrate budding community despite slow Internet
Associated Press
7/4/11 Cuba would hurt if Chávez is replaced
By Juan Tamayo, The Miami Herald
7/1/11 Cuba plans limited housing and auto market
By Marc Frank, Reuters
7/1/11 Chávez Says a Cancerous Tumor Was Removed
By Simon Romero, The New York Times
7/1/11 US must step up Cuba oil spill readiness - experts
By Jeff Franks, Reuters
7/1/11 U2’s Bono urged support for Cuban dissident Biscet
By Juan Tamayo, The Miami Herald
7/1/11 New Ways to Visit Cuba — Legally
By Michelle Higgis, The New York Times
7/1/11 Cubans honor ashes of New York pastor Walker who defied US embargo with 21 aid trips to island
Associated Press