MIAMI (Reuters) -- A disabled tanker was adrift near the world's third
longest barrier reef but the U.S. Coast Guard said there was no immediate
threat to the fragile coral reef off Florida's coast.

The double-hulled tanker Isarstern was not loaded with cargo but carried
90,000 gallons of marine diesel fuel and 20,000 gallons of lube oil, the
Coast Guard said Thursday.

The 529-foot ship, flagged in the Isle of Man, was on its way to Houston
from Quebec, Canada, when its engine failed early Thursday off Marathon in
the Middle Keys.

It was about two miles from the Florida Keys National Marine Sanctuary and
dropped anchor to slow its drift toward the park's shallow waters, the
Coast Guard said.

"It is slowly drifting east-northeast, parallel to the Florida Keys
National Marine sanctuary boundary, presenting no immediate threat to the
sanctuary," said Coast Guard spokeswoman Danielle DeMarino.

The sanctuary surrounds the Florida Keys chain of islands and is home to
the United States' only living barrier coral reef. It is the third longest
barrier reef in the world, after Australia's and Belize's.

Crewmen were trying to repair the ship's engine and a commercial salvage
vessel was expected to reach the tanker early Friday, DeMarino said. A
Coast Guard safety officer was aboard the disabled ship.