ABC News' Gio Benitez and Katie Kindelan report:

It took Diana Nyad five attempts to become the first person ever to swim from Cuba to Florida without a shark tank, but it took just days after she completed her record-breaking swim last week for critics to question whether the 64-year-old really completed the 110-mile swim on her own.

Members of MarathonSwimmers.org, a members-only forum for distance swimmers, have been examining stroke speed, currents and other factors to determine whether Nyad was telling the truth about her 53-hour swim. Nyad's critics have also been skeptical about the speed with which she completed the journey and a 7-hour stretch in which she reportedly went without food or drink.

The Mantra That Drove Diana Nyad to a Record-Breaking Swim

Just as she did with her determination in breaking the Cuba-to-Florida record, Nyad is addressing the critics head on, saying she only has Mother Nature to thank for allowing her to finally complete her dream.

"Did I finally, after five times, get some luck with the current rather than bad luck? Yes, we got a great Gulf Stream," Nyad told ABC News.

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Nyad's navigator, John Bartlett, said during a nearly three-hour conference call he and Nyad held Tuesday night with members of the marathon swimming community that the Gulf Stream was so powerful it helped Nyad reach speeds of up to five-and-a-half miles per hour, nearly five times her regular swimming speed.

Nyad said at a press conference last week that she was surprised at how fast the swim went. Her best friend, Bonnie Stoll, told her that she was on pace to arrive in Key West a day earlier than planned.

"I said, 'What about Monday night?' and she said, 'You're not going to be swimming Monday night,'" Nyad said, standing up and pounding her chest with her hand. "All that trepidation I was feeling just rose up, and now we were going again; now we're going."

See Diana Nyad Talk About Her "Hell On Earth" Swim

In response to swimmers' requests that Nyad and her team release the raw data from her swim, Nyad said on the call, "It should be out there for all the world to see. We are not holding anything from you."

Nyad told ABC News her critics' questions of whether she left the water or was aided by her support team beyond the allowable guidelines of handing her food and assisting her with her jellyfish suit are unfounded.

"We never, ever touched a boat," she said. "We did this thing squeaky clean."

Nyad's first words when she reached the shores of Key West on Sept. 2, surrounded by throngs of fans and the media, quickly became a mantra for what she had accomplished.

"Never, ever give up," she said.

Now, despite her critics, Nyad says her accomplishment and her words have not been diminished.

"I know they haven't for me," she told ABC News. "I know what we did. I hope the public is savvy and world records deserve to be scrutinized before they are officially applauded."

ABC News' Colleen Curry contributed to this report.