The rescue happened Monday. The adventure started five days prior.
The Coast Guard says a 54-year-old man got stranded on Roe Island after his raft began to sink. He was able to talk to family and tell them he needed rescue, but he didn't know his location.
Officers used that information to help locate him, but it took some time. The man told his family he could see Naval vessels and that he could hear reveille every morning. The Coast Guard said it also reached out to the man's cell phone provider for GPS information and determined he must be near the Concord Naval Weapons Station.
Once they could pinpoint an area, the Coast Guard launched a boat from Station Vallejo. They found him waving a red flag.
The boater was taken to a pier in Martinez with no serious injuries.