Although a specific date was not given for the recovery of the U.S.S. Wenonah, a spokesman said the salvage effort will begin the week of Aug. 24.
The 100-foot Wenonah is still resting on the bottom of the San Francisco Bay near Pier One on Treasure Island, submerged except for the top few feet of its mast in 25 feet of water.
The tugboat sank on Aug. 17, and an oil spill ensued when residue from the engine leaked out into the bay, according to the Coast Guard.
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 said.
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.
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.