Ships flee BP spill site as storm comes

Engineers prepared to abandon their vigil over BP's broken oil well Friday as ships and rig workers leavethe Gulf of Mexico ahead of tropical depression Bonnie.

The mechanical plug that's throttled the oil for a week will be left closed, even if the undersea robots monitoring the well's stability leave. BP will have to rely on satellite and aerial views of oil gushing to the surface to know if the cap fails.

Retired U.S. Coast Guardadmiral Thad Allen said he's confident the cap will hold, despite a few leaks that raised concerns last week.

Scientists said even a severe storm shouldn't affect the plug, more than 1.5 kilometres beneath the ocean surface nearly 70 kilometres from the Louisiana coast.

Bonnie had been a tropical storm, but was downgraded by officials at the U.S. National Hurricane Center late Friday afternoon.

She made landfall in Florida south of Miami on Friday morning with top sustained winds of 65 km/h. The storm was on track to pick up strength as it crosses the Gulf of Mexico, reaching the site of the massive oil spill by Sunday.

The hurricane centre saidBonnie came ashore Friday midday near Cutler Bay, about 30 kilometres south of Miami. There were no immediate reports of damage.

The rough weather could delay by another 12 days the push to plug the broken well for good using mud and cement, Allen and BP officials conceded. The storm already has pushed back efforts to kill the well. BP had hoped to finish drilling the relief tunnel on Friday, but had to plug it on Wednesday to prepare for the storm.

"Preservation of life and preservation of equipment are our highest priorities," Allen said.

Rigs pulling pipe, leaving

The rigs working to plug the well were pulling up more than 1.5 kilometres of pipe and will start moving to safer waters later Friday, Allen said.

Ships carrying the robotic submarines watching the well will be the last to leave likelyin about two days and the first to return.

"If conditions allow, they will remain through the passage of the storm," Allen said.

Audio surveillance gear left behind could tell BP whether the well is unstable, butcrews won't be able to listen to the recordings until the ships get back into the area.

The delay in work would be worse if BP had to open the cap while the ships closely monitoring the wellhead left. More oil would have been allowed to spew into the Gulf until they returned.

Shell Oil is also evacuating its operations in the Gulf, moving out more than 600 workers and shutting down production at all but one well.