The Marin County Fire Department, U.S. Coast Guard and other agencies are searching an area of Muir Beach where a small boat was found capsized Wednesday morning.
A chest containing ice and fish and other debris was found in the water after someone aboard "The Zodiac" vessel reported the capsized boat, about 14 feet long, on a marine radio channel to the Coast Guard around 11:30 a.m., Marin County Fire Battalion Chief Bret McTigue said.
"There's strong evidence someone was on board," McTigue said.
The response is still considered a rescue operation, he said.
The National Park Service, Southern Marin Fire Protection District, Muir Beach and Stinson Beach fire departments and helicopters from the Sonoma County Sheriff's Office, California Highway Patrol and Coast Guard Air Station San Francisco are participating in the search.
The Marin County Fire Department was able to re-right the boat, which did not have identifying markings on it, McTigue said.
The water near the shoreline where the boat was found is about 30-40 feet deep and dive teams are standing by, he said.
Three Coast Guard boats, six Jet Skis and an inflatable boat are at the scene, McTigue said.
Firefighters were attending a Jet Ski rescue training class nearby when the report about the capsized boat was received.
"We were able to put rescuers in the water in 12 minutes," McTigue said.