The Coast Guard received an emergency call for help on Sunday, a rough day at sea for which severe-weather advisories had been issued. A married couple and two young boys were reportedly on the disabled boat. The man who made the distress call said the boat was taking on water and its onboard electronics were not working, including its vital GPS devices.
Investigators used a radio signal from the boat and radar and determined the distress call came from about 60 miles west of Monterey. The 29-foot sailboat is thought to be named the "Charmblow."
The distress call said the family was abandoning ship and was preparing to use flotation devices.
Authorities think the call may have been a hoax. No families or boats have been reported missing in the days since the distress call was received. Rescuers have been searching the surrounding area by sea and by air.
Harbor masters at the string of ports that dot the coastline from Monterey to Half Moon Bay told The Associated Press the same thing: No boats launched from their docks were missing, and no family had disappeared from their community.
FBI spokesman Peter D. Lee in San Francisco said the agency was not investigating and had received no missing-persons reports that could be this family.
Neither officials nor boaters had heard of a vessel called "Charmblow." But several noted that boats are registered in California by number, not name. Owners can call a boat whatever they want. Federally registered boats use names, but there was no "Charmblow" listed on the federal database.
Coast Guard officials say they're still tallying the rescue efforts' cost but estimate it ran into the hundreds of thousands. The search also included the California Air National Guard.
The Associated Press contributed to this report.