OLYMPIA – Divers today confirmed that fuel tanks inside a sunken vessel in Orcas Island’s West Sound are empty.

The spill response led by the Washington Department of Ecology (Ecology) and the U.S. Coast Guard is now ramping down.

The vessel had 250 gallons of diesel on board before it sank yesterday. Most of the fuel was consumed in the fire and that about 50 gallons went into the water, estimated Carl Andersen, an Ecology spill responder.

Although an oil sheen is still visible, responders consider the remaining diesel to be unrecoverable. The responders will remove oil spill containment boom when they believe absorbent pads are no longer taking up new oil.

The remaining fuel in the water will dissipate naturally over time with wind and sun. Responders do not expect it to come into contact with the shoreline.

All oil spills cause environmental damage, regardless of size. Oil is toxic to the environment and the damage starts as soon as the oil hits water. A single quart of oil has the potential to foul more than 100,000 gallons of water.

The sunken vessel is the 47-foot Coho, owned by Peter McCorison of Eastsound. Yesterday afternoon while it was moored at West Sound Marina, it caught fire, broke from its mooring, drifted away and eventually sank. The Coast Guard Cutter Blue Shark, an 87-foot patrol boat homeported in Everett, Wash., was in the area and responded to the fire and was able to extinguish it.

The initial containment “boom” that the cleanup contractor placed around the spill came from one of the oil spill caches that Ecology has strategically placed around Puget Sound. The emergency supply of oil spill materials was stored at nearby Deer Harbor.

Before darkness last night, the Coast Guard conducted an over flight to see the extent of the spill. And, after dark, Ecology requested the Washington State Patrol to conduct an over flight of the spill to use infrared technology to assess the success of the containment boom that circled the spill scene.

The burned vessel eventually sank in 57 feet of water. Although there was no spill initially, a rainbow sheen of diesel fuel from the vessel developed and grew throughout the afternoon. Earlier today, responders observed a sheen that was about one mile long and about 200 yards wide that was moving north.

Island Oil Spill Association, Ballard Diving and the San Juan County Fire Department assisted the incident response.