Bay Area swimmer prepares for historic attempt to swim entire California coast

A Pleasanton endurance swimmer is preparing to attempt what she says has never been done before: swimming the length of California’s coastline.

Katherine Breed plans to enter the Pacific Ocean at the Oregon border next week to begin “Swim California,” an expedition that she estimates will cover about 900 miles.

“This has never been attempted,” Breed told ABC7 Eyewitness News in an interview. “There have been similar expeditions around the world, one around Iceland last summer, Ireland, and a few people have from the coast of Great Britain. But nothing like this, swimming down the coast of California.”

MORE: Search suspended for missing California swimmer after possible shark attack

Breed said the route is slightly less than 900 miles “as the crow flies,” but currents and other conditions mean swimmers typically travel farther than the direct distance.

She said the challenge is driven by both a personal connection to the coast and a broader mission.

“I grew up swimming, and sailing in the San Francisco Bay and on the Pacific,” Breed said. “I get to do this thing I love, and I get to learn more about the coast.”

She added that the expedition is intended to raise awareness about ocean conservation and coastal communities.

“The bigger reason, the why that’s greater than myself, is to tell a story of the coast, to raise awareness for the people, places, the problems, ocean conservation issues happening in our very own backyard,” Breed said.

Breed also said she founded a nonprofit aimed at encouraging more women and girls to get into the ocean.

“Because, I believe if you learn about something and you fall in love with it, you’re going to fight to protect it,” she said.

According to Breed, the expedition has been more than three years in the making and involves a large support team.

She plans to swim about five hours each day, covering roughly 10 to 15 miles daily, typically during the early morning when winds are lighter.

A 52-foot Beneteau sailboat will serve as the primary support vessel.

Breed said the team expects to return to harbors regularly, except in stretches of coastline where no harbors are available, including portions of the Lost Coast and Big Sur regions.

The swimmer said she expects the journey to take at least three months, though weather conditions could extend the timeline.

“One thing about our coast is it can be pretty volatile, and the winds can kick up,” Breed said. “We did a lot of buffer to adjust, so that we’re not racing the clock. I don’t want to forgo safety at the expense of manufactured timeline that we made.”

MORE: Cause of death for swimmer found in Santa Cruz County beach revealed by coroner

While sharks are among the risks many people ask about, Breed said weather-related hazards are a greater concern.

“I actually think that’s very low on our risk,” she said of sharks, noting that the expedition will include a support craft and shark deterrents.

Instead, she pointed to storms, wind, fog, fishing gear and offshore rocks as some of the challenges the team expects to navigate.

Breed said she will wear a wetsuit during the swim, a departure from many of her previous long-distance swims that followed English Channel rules requiring only a swimsuit, cap and goggles.

“I intentionally decided to wear wetsuit,” she said. “I’m wearing the wetsuit just to control the controllables, so I don’t need to worry about getting cold or sunburnt, and it will definitely protect you against jellyfish.”

Breed said the expedition is scheduled to begin July 1, though a July 2 start remains possible.

She said people can follow the journey through her social media accounts, website and YouTube channel, where updates and live tracking are expected to be available throughout the swim.

Bay Area swimmer prepares for historic

If you’re on the ABC7 News app, click here to watch live