Marathon swimmer Catherine Breed began her 900-mile swim down California’s coast from the Oregon border Wednesday where she’ll swim for five hours a day with the goal of reaching the Mexican border by November.

Catherine Breed's expedition, dubbed "Swim California," began early Wednesday morning and will take her roughly 900 miles from the Oregon border to the Mexican border over the next four months, as the Chronicle reports. If successful, she would become the first person to swim the entire California coast.

According to the New York Times, the marathon swimmer, who was born and raised in Mill Valley, will spend five to eight hours in the water, swimming one to two miles offshore, and covering about 10 to 15 miles a day when conditions allow, while facing cold water, rough seas, powerful currents, jellyfish, elephant seals, and great white sharks.

“I can swim through almost anything when I’m in the water,” Breed said, speaking to the Chronicle.

Breed will reportedly live aboard a 52-foot sailboat with a support crew that will track her progress, monitor safety, document each stage for official world-record verification, and return her to the previous day's stopping point each morning. She'll pause every 30 minutes for quick nutrition breaks without touching the boat and plans to come ashore periodically for public events promoting ocean conservation through her nonprofit, Sea Dreamers.

Breed swam at the University of California, Berkeley before turning to marathon swimming, where she's already set records and completed crossings of Lake Tahoe and the Monterey Bay, as well as the English Channel and the North Channel between Scotland and Ireland, per the Times.

As SFist reported last year, Breed set the fastest recorded swim from the Farallon Islands to the Golden Gate Bridge in August, completing the 30-mile crossing in 13 hours, 54 minutes and 10 seconds — about four minutes faster than the previous record.

While the Swim California presents plenty of challenges, Breed said she's most excited to experience remote stretches of the California coast few people ever see.

“I’m getting to experience parts of the coast that have never been experienced in this way before,” she told the Times. “No one goes slowly down the California coast.”

Previously: Mill Valley Woman Breaks Record for Fastest-Ever Swim From Farallon Islands to SF

Top image: Courtesy of Swim California