The three aircraft were returning from the Pacific Coast Dream Machines show Sunday in Half Moon Bay south of San Francisco. Jimmy Lee, a spokesman for the Contra Costa County Sheriff's Office, said the wreckage of the crashed plane, a 1965 Cessna 210, was found Monday.
The pilot, who was alone in the plane, is believed to be dead, although officials had not said Tuesday morning whether a body was found. The plane was found a mile and a half offshore in 13 feet of water.
The other plane involved was a restored Hawker Sea Fury TMK 20, a British fighter from the early 1950s. It landed safely at its home airport, Eagle's Nest in Ione -- about 40 minutes east of the crash site -- with the husband and wife on board unhurt.
Witnesses said the planes were close to each other as they headed east near Richmond, suggesting they were flying in formation.
"Formation flying is very technical. It has to be well briefed. It has to be choreographed exactly to the brief, and it has to have a high level of communication if in fact they were doing formation flying," Sean D. Tucker, an aerobatic pilot who has flown in formation over the area, told the San Francisco Chronicle.