Someone walked into the fire station on Johnson Street in Sausalito shortly after 5 p.m. to report spotting what appeared to be a body while hiking in the Kirby Cove area, Capt. Mike Martinez said.
Martinez said the body was found hundreds of feet from the water and was clad in a wetsuit and jacket.
Golden Gate National Recreation Area spokesman Howard Levitt said the body was retrieved by the Marin County coroner's office.
The National Park Service is investigating the death, and treated the area around the body as a crime scene, as is standard procedure.
Levitt said no further information about the body or the person's identity was available.