The Coast Guard initially responded to the area after a pedestrian reported seeing a man's body about one mile south of Salmon Creek at 1:30 p.m., Coast Guard Lt. j.g. Jeremy Pichette said.
Authorities were able to recover the body after it washed ashore, Pichette said.
The Coast Guard then learned that two people had taken their 20-foot boat out this morning to lay crab pots and had not returned, according to Pichette.
The Coast Guard, along with the Sonoma County Sheriff's Department and the National Park Service, launched a search for the vessel and a possible second victim. At about 4:15 p.m., a second body, that of an elderly woman, was located near an overturned vessel, also south of Salmon Creek, Pichette said.
He said the two victims match the description of the pair that set out earlier in the day to lay crab pots.
Due to rough water conditions, authorities decided it was unsafe to attempt to recover the vessel, Pichette said, adding that the Coast Guard will monitor the boat overnight.