SAN FRANCISCO (KRON) — Open-water swimmer Catherine Breed swam from the Farallon Islands to San Francisco’s Golden Gate Bridge, a chilly 30-mile journey through some of the Pacific Ocean’s most notorious great white shark territory.

Breed said she completed her 30.6-mile swim Tuesday in 13 hours, 54 minutes.

The Pleasanton native was assisted by an expert boat crew that followed Marathon Swimmers Federation rules: swimmers may not use a wetsuit and they can’t touch the boat.

Breed, 32, said in an Instagram video, “My body was OK, but my mind was not in a great spot. It’s like the islands and the ocean gave me a perfect day but infiltrated my head with doubt. Of all the swims I have done, this one was the mentally hardest.”

“Doubt is a really powerful negative emotion,” the swimmer said. “I’m so glad I had a full team of people that believed in me. In your life, surround yourself with people like that.”

The 6-foot-tall ultra endurance athlete grew up competing for Amador Valley High School and UC Berkeley’s swim teams in the 500, 1,000, and 1,650 freestyle.

She is a world-record holder for the fastest female swim across Lake Tahoe.

Open water ocean swimming is a far different challenge. The Farallon Islands, also known as “Devil’s Teeth,” are rocky and isolated.

“It wasn’t the distance that made this swim unique, it was all the other factors. The best time of year to swim it also happens to be during great white migration, the currents change quickly and dramatically. A good portion of the swim occurs in very deep dynamic water,” Breed wrote.

Jellyfish stung Breed’s neck and arms early into the swim. “Everyone wants to know about the sharks. I wanted to see what dark, sharky waters felt like,” she said. “Usually you can sense them.”

Every time Breed wanted to quit, her boat support crew mentally pushed her to keep going, she said.

Breed was counting on a strong and favorable current that usually flows near San Francisco to help her reach the finish line Tuesday. The current, unfortunately, never materialized for the shivering swimmer.

“I felt like the city was moving away from me. I turned on this gear that I didn’t know existed,” she said. “I was swimming race pace for the last hour and a half.”

Few swimmers have ever completed the 30-mile swim due to brutal and cold conditions. Breed became the 3rd-ever woman to do it.

“The Farallons swim is the epitome of wild,” Breed said. “The ocean is both beautiful and humbling. Adventure still exists right here off our coast. The ocean belongs to everyone, and I want to inspire people –especially women and youth — to believe that big things are possible, even when they seem wild or impossible.”