ANTIOCH (CBS SF) – It will take weeks to move an 87-foot private boat from the spot where it capsized Sunday near Bethel Island in eastern Contra Costa County, U.S. Coast Guard officials said.

To prevent the estimated 600 gallons of diesel on board the “Spirit of Sacramento” from spilling into the False River, Global Diving & Salvage Inc. plugged all fuel vents on Monday, according to the Coast Guard.

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The vessel capsized at around 12:30 a.m. in the small river between Franks Tract and the San Joaquin River. Two people on board rescued themselves by using a dinghy.

Coast Guard officials believe the boat has 600 gallons of fuel on board, though they said an analysis of the boat’s schematics shows that the vessel can hold up to 4,500 gallons.

The Coast Guard and the salvage company are monitoring the area and are ready to contain any fuel that the boat might release.

A two-phased response to recovering the vessel will consist of about three weeks of preparation to bring the boat to the surface and then removing the fuel, according to Coast Guard officials.

The boat does not pose a hazard to other boats navigating the area, but Coast Guard officials suggest boaters use caution where salvage operations are going on.

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Because of the size of the boat, the possible amount of fuel onboard and the potential for a complex fuel removal process, Coast Guard officials have opened the Oil Spill Liability Trust fund to quickly take action to protect the environment.

The fund was set up to help pay for assessing damage and recovering oil from a spill. The party responsible for the boat must pay cleanup costs and damages.

Coast Guard officials said they have not yet identified who owns the vessel. The boat used to be a commercial vessel that carried passengers and had to be inspected by the Coast Guard.

But someone has since purchased the boat for recreation only, Coast Guard Lt. j.g. Nicole Emmons said. More than one vessel has the name Spirit of Sacramento, Coast Guard officials said.

The Coast Guard could not immediately estimate the cost of bringing the boat to the surface and recovering the fuel because the recovery is ongoing.

Emmons said Coast Guard officials do not know yet what caused the vessel to capsize.

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