A cap was back in place on BP’s broken oil well in the Gulf of Mexico after a deep-sea blunder forced crews to temporarily remove what has been the most effective method so far for containing some of the massive spill.

Also, as oil washed up on once- pristine Florida beaches, U.S. District Judge Martin Feldman rejected a Justice Department request that he delay his ruling overturning the administration’s drilling moratorium.

Engineers placing the cap back over the gusher used remote-controlled submarines to reposition the cap late Wednesday after it had been off for much of the day. It had captured 700,000 gallons of oil in the 24 hours before one of the robots bumped into it.

Bob Dudley, BP’s new point man for the oil response, said removing the cap was the right move because fluid seemed to be leaking and could have been a safety hazard.

“It’s a setback, and now we will go back into operation and show how this technology can work,” he said before the system was working again.

While the cap was off, clouds of black oil gushed unchecked at up to 104,000 gallons per hour, though a specialized ship at the surface managed to suck up and incinerate some.

The oil-burning ship is part of an armada floating at the site of the rogue well some 50 miles off the Louisiana coast, and the scene below the surface is no less crowded.

At least a dozen robotic submarines dangle from ships at the surface on mile-long cables called “umbilicals,” with most of the undersea work taking place within a few hundred yards of the busted well.

Crews of three operate each machine from control stations using joysticks and banks of video screens, inching them through the small portions of the pitch-black water that the submarines’ headlamps can illuminate. Sometimes the water gets so murky that the controllers operate essentially by sound — the robots can map their surroundings using sonar.

Using the machines’ mechanical arms, highly trained pilots routinely perform delicate jobs such as switching valves on, turning wrenches and grasping wires no thicker than phone cords. Accomplishing even the smallest of tasks at such depths with robots the size of Humvees can be so tricky that experts compare it to remote-control surgery.

Only one other time during the attempts to contain the nine-week-old leak — when a submarine jarred loose a tube that been sucking oil from the broken riser — has one of the robot crews interrupted those efforts, said Coast Guard Adm. Thad Allen, the Obama administration’s lead spill responder.

“I think the fact that we’ve had two bumps that have had some kind of a consequence associated with them in the 60-plus days response is a pretty good record,” he said. “It’s never going to be risk-free out there, and we need to watch it very closely.”

The latest problem in the effort to stop the gusher came as thick pools of oil washed up on Pensacola Beach in Florida, and the Obama administration sought to resurrect a six-month moratorium on deepwater drilling off the U.S. coast.

Britain, where BP is headquartered, said deep-sea exploration will continue in North Sea oil fields off Scotland despite safety concerns raised by the spill, the country’s energy minister said Thursday.

Energy Secretary Chris Huhne told an energy conference in London that regulation is strong enough “to manage the risk of deep-water drilling.” Britain announced this month it was doubling the number of inspections carried out at the North Sea rigs following the Gulf disaster.

The current worst-case estimate of what’s spewing into the Gulf is about 2.5 million gallons a day. Anywhere from 68.5 million to 130 million gallons have spilled since the April 20 explosion on the Deepwater Horizon rig that killed 11 workers and blew out the well 5,000 feet underwater. BP PLC was leasing the rig from owner Transocean Ltd.

In Florida, thick pools of oil washed up along miles of national park and Pensacola Beach shoreline as health advisories against swimming and fishing in the once-pristine waters were extended for 33 miles east from the Alabama line.

“It’s pretty ugly, there’s no question about it,” said Florida Gov. Charlie Crist.

The oil reeked as it baked in the afternoon heat on a beach that looked as if it had been paved with a 6-foot-wide ribbon of asphalt.

“This used to be a place where you could come and forget about all your cares in the world,” said Nancy Berry, who fought back tears as she watched her two grandsons play in the sand far from the shore.

Meanwhile, U.S. District Judge Feldman rejected a Justice Department request that he delay his ruling overturning the administration’s drilling moratorium.

The Interior Department imposed the moratorium last month, halting approval of any new permits for deepwater projects and suspending drilling on 33 exploratory wells.

Interior Secretary Ken Salazar said he would issue a new order within the next few days imposing a moratorium that eliminates any doubt it is needed and appropriate.

Separately, a number of environmental groups asked the court to release additional information about Feldman’s financial interests.

The judge’s financial disclosure report for 2008, the most recent available, shows holdings in at least eight petroleum companies or funds that invest in them, including Transocean Ltd., which owned the Deepwater Horizon. The report shows most of his holdings were valued at less than $15,000; it did not provide specific amounts.

The environmental groups want to know whether Feldman has a financial interest that could be substantially affected by the outcome of the proceeding. If so, he could be forced to disqualify himself from the case.