By Chris Francescani
NEW YORK (Reuters) - U.S. long-distance swimmer Diana Nyad vigorously defended on Tuesday her record-breaking, 110-mile (177-km) swim from Cuba to southern Florida after skeptics raised questions about the grueling trek.
"I swam ... in squeaky-clean, ethical fashion," Nyad told a conference call late on Tuesday that included journalists and fellow marathon swimmers, some of whom have publicly questioned aspects of her challenging journey.
"I honored the rules," Nyad said at the start of the conference call. "I was an ethical swimmer."
A triumphant Nyad, 64, staggered ashore in Key West, Florida, on September 2, after having swum about 53 hours, to become the first person to complete the treacherous crossing without a shark cage.
Nyad's swim was her fifth attempt and only successful one. The highly publicized crossing sparked a social media debate about whether her journey meets the requirements to break the world record.
Some have questioned how Nyad was able to more than double her pace about halfway to Florida, and have wondered whether she was towed at any points by tracking boats.
Marathon swimmer Evan Morrison was among a number of members of the long-distance swimming community who publicly questioned Nyad's feat on social media.
"In reading through Diana's crew's live-blog, trying to suss out how this incredible swim happened, I was struck by how little information there actually was," Morrison wrote on the online Marathon Swimmers Forum.
"These details matter because Ms. Nyad is claiming - and the media reporting without fact-checking - a new world record for longest-distance nonstop, unassisted ocean swim," he said.
Nyad's pace quickened significantly about halfway through the swim - from her average 1.5 miles per hour to nearly four miles per hour - a swift pace that continued for about six hours.
She and her supporters have said that she got a significant boost from a favorable Gulf stream current - a contention that independent experts who study the ocean currents in the region agreed with on Tuesday.
Mitchell Roffer, who runs a Melbourne, Florida-based ocean fishing forecasting service, said Nyad caught a swift, north-moving current, and then turned east out of the current at precisely the right moment.
"To me, it was an oceanographic lotto that she hit," Roffer told Reuters. "You can't get much luckier than she did."
"The current, which was pulling her in north-northwestern flow, was as perfect as you could get," Roffer said. "It would explain why her speed was faster during that period."
John Bartlett, one of Nyad's navigators, said on the call that Nyad's speed for nearly six hours - beginning about halfway through the trek - averaged 3.97 miles per hour.
Nyad, who was patient and in good spirits while answering numerous detailed questions from colleagues and reporters, said that during "this record-breaking swim I never touched the boat, not even an inadvertent touch."
But after more than two hours she grew briefly exasperated with her inquisitors. She said that in the eight days since the race, she has had little time to review all the media coverage.
"First of all I was trying to feel some joy," she said. "It's something I've wanted to do all my life. Most of that joy stopped when, you know ... you always expect some questioning but my own peer group, instead of coming to me and asking me questions went to the media."
Asked why she didn't better prepare to document the 53-hour swim with more video cameras that could have answered skeptics' questions, she said that after four failed attempts, most of the world had given up on her.
"My own family were like, 'Please Diana, just give this up,'" she told reporters. "Nobody wanted to be out there with us."
She said she wished some of those now requesting so much documentation to prove she broke a record were there before she left Cuba.
At the start of her most recent attempt, she said mockingly to skeptical journalists, "I didn't get any emails from any of you ... saying, you know, you really should have someone from the Obama administration" trailing to document the journey.
The comment drew laughter, but Nyad then grew more serious, and it became clear she was hurt by the skepticism of colleagues in the tiny global community of marathon swimmers.
"I never ever knew that we would not be trusted," she said.
The previous record was held by Australian Penny Palfrey, who attempted the same crossing without a shark cage in 2012. Palfrey swam about 80 miles in 41 hours before adverse currents forced an end to the attempt.
(Reporting By Chris Francescani; Editing by Tim Gaynor and Eric Walsh)