Salvage operations for the historic tugboat that sank off the coast of Treasure Island will begin this week, according to the U.S. Coast Guard.
Someone walking along the shore last Monday reported the tug was sitting low in the water. But that night, the boat was completely submerged with only the mast above the water line.
The 100-foot U.S.S. Wenonah is still resting on the bottom of the San Francisco Bay near Pier One on Treasure Island.
A small amount of oil spilled into the bay.
Cleanup crews quickly removed 200 to 300 gallons of an oily water mixture, and as of Friday, costs had totaled $100,000.
The Coast Guard still doesn't know why the Wenonah sank, and although divers have been investigating it underwater, a final determination can't be made until the boat is salvaged, according to Lt. Cmdr. Gus Bannan, chief of incident management for the San Francisco division.
The water is murky. Divers can only see a few inches so the dives have been mostly a touch and feel exercise.
It's also unclear who will pay for the salvage or how much it will cost, but Bannan said the oil cleanup was paid for with funds from the federal Oil Spill Liability Trust Fund.
The Wenonah is owned by the Historic Tugboat Education and Restoration Society, which leases the space at Pier One on Treasure Island.
The U.S.S. Wenonah was built in 1940 and spent 33 years in service before it was decommissioned in 1974.
Bay City News contributed to this report.