Members of the Alameda County dive team retrieved the body of the 25-year-old man at about 2:30 p.m. Saturday.
According to an Alameda County Water District official, the man dove off the railroad bridge and into the 16-foot deep water. His body was recovered near the depth markers.
According to the Alameda County Sheriff's Department, the man was there with two friends. The call for help came into 911 around 11:30 a.m.
One of the friends said the man dove into the Alameda Creek and never resurfaced.
Three hours later, his body was recovered by divers.
The area is clearly marked with "no swimming" signs.
It's not yet clear if the man hit something underwater, or why he didn't resurface. His body is now with the county coroner and an autopsy may provide some of those answers.
The identity of the man has not yet been released. But we briefly talked with a water district official who says the man may have just gotten out of the U.S. Navy.