Deepwater diesel cleanup stalls at San Juan Island shipwreck

U.S. Coast Guard officials say divers won’t be able to reach the Aleutian Isle, a sunken fishing boat off San Juan Island, until Monday or Tuesday at the earliest.

The purse seiner was carrying an estimated 2,500 gallons of diesel when it sank while trying to net sockeye salmon on Saturday, Aug. 13.

An unknown amount of that diesel spilled, forming a thin sheen that spread for 2 miles up and down the island’s west coast and into Canadian waters over that weekend.

By Friday afternoon, the visible pollution had mostly evaporated and shrunken to a 50-foot by 100-foot light sheen above the sunken vessel, according to the Coast Guard.

Coast Guard officials say it’s unclear from underwater drone video whether any diesel – a clear liquid – is still leaking from the boat, but the Aleutian Isle’s fuel tanks appear intact.

Humans have yet to visit the Aleutian Isle since it sank.

On Monday, divers descended to where a sonar scan had showed the boat resting on the sea floor, but they discovered that currents had moved the boat to much deeper water since the Saturday scan.

The boat is now sitting in such deep water — more than 210 feet at the bow and 240 feet at the stern — that Global Diving and Salvage, the Seattle company hired to remove the remaining diesel, has had to order and wait for specialized equipment and gases to allow divers to work safely.

At those depths, commercial divers often breathe a specialized mix of helium and oxygen to avoid potentially fatal hazards such as nitrogen narcosis.

Between the extreme depths and the dangerous currents that often flush through Haro Strait, divers will have to work quickly before returning to the surface.