A 29-year-old man visiting from Wyoming was struggling in the water when crewmembers aboard a Blue & Gold ferry en route to Tiburon spotted him, Coast Guard Petty Officer Danielle Couture said.
The crew of the MV Zelinsky, which departed San Francisco around 5:30 a.m., placed a call to the Coast Guard alerting them of the situation.
But when the man - who was wearing a wetsuit, lifejacket and a camouflage vest - was taken aboard, the ferry captain mistook his camcorder and other personal belongings for a gun and possibly explosives, Couture said.
At that point the Coast Guard coordinated efforts with police on the ground in Tiburon to have the man detained upon arrival.
No other passengers were aboard the ship when it docked in Tiburon at 6:11 a.m., she said.
Once on steady land, Couture said police determined the camcorder was indeed a camcorder.
It is unclear if the swimmer made it back to San Francisco.
During the confusion, the Coast Guard adhered to standard procedures when there is a fear of explosives: they dispatched a small boat with a law enforcement team on board and set up a safety zone in the area. The safety zone is created for the protection of other mariners on the water.
The Tiburon Police Department could not be reached for comment as of 7:15 a.m.
A dispatcher with Blue & Gold said the ferry would complete its commuter runs this morning before the operator returns to fill out a report of the incident.