The body was found in the water by a harbormaster just before 11 a.m. Sunday, the sheriff's office said. The third victim has not been identified and no details on the gender were given at this time.
Last week, the coroner's office identified a second body that was found. She was identified as 26-year-old Cassidy Rae Petit of Oakland.
RELATED: Couple killed in plane crash near Half Moon Bay was 2 weeks away from wedding day, obituary says
An obituary published online says Petit, and her fiancé, 27-year-old Lochie Ferrier, died on Jan. 14 when their plane crashed.
Petit and Ferrier were just two weeks away from their wedding in Hawaii.
Isaac Zimmern, 27, and his partner Emma Pearl Willmer-Shiles were the other couple on board at the time.
RELATED: Coroner ID's woman whose body was found near site of Half Moon Bay coast plane crash
Willmer-Shiles was the first victim identified on Jan. 15 after being recovered near the site of the crash.
According to federal investigators, the small airplane that crashed was a home-built plane.
The National Transportation Safety Board said it had preliminary information that there were four people on board.
Initially, the Federal Aviation Administration reported there were only two people on the plane.
The cause of the crash is still under investigation.
The video in the player above is from a previous report.