After a string of failed attempts to cap the leak, BP is battling to contain the six-week-old spill, now the worst in US history, with robotic submarines working in cold waters a mile down (1,600 meters) on the sea bed.
Efforts were temporarily bogged down Wednesday when the saw being used to cut through the fractured riser pipe became stuck but later freed, with the live video feed no longer showing the diamond wire saw stuck in the pipe.
The saw was being used to cleanly cut off the ruptured riser pipe at the top of a failed blow-out preventer, to cap the end of the pipeline and then siphon the oil to a containment ship on surface.
The latest official projections from the National Oceanic and Atmospheric Administration (NOAA) show the slick to be about seven miles (11 kilometers) off Florida's shores and officials warned its arrival on pristine tourist beaches is imminent.
Florida Governor Charlie Crist warned that forecasters "are projecting weathered oil from the leading edge could impact the Florida Panhandle as early as this week, possible in a day or two."
"We are watchful, we are monitoring the situation, and we will do everything to protect our beautiful state," he told a press conference, warning "thousands of tar balls" could be approaching the state.
Florida would be the fourth state hit by the oil since an April 20 explosion ripped through the Deepwater Horizon rig, 50 miles (80 kilometers) off the Louisiana coast, killing 11 workers.
More than 125 miles (200 kilometers) of Louisiana coast have been contaminated, triggering long-term fears for the region's already endangered wildlife.
A University of Miami study meanwhile showed the oil slick's surface area now stretches across 9,435 square miles (24,435 square kilometers) of the Gulf -- triple the size of satellite imagery from May 1.
Experts warn also that the vast majority of the oil is contained in vast underwater plumes that cannot be measured by analyzing from above.
US officials closed more than a third of Gulf of Mexico waters, extending a fishing ban to 88,502 square miles (229,219 square kilometers) -- about 37 percent of the Gulf's federal waters.
The NOAA said the closures were precautionary "to ensure that seafood from the Gulf will remain safe for consumers," but the most significant expansion of the closed fishing area included a zone off southwest Florida just off Dry Tortugas islands.
The massive spill has frayed the nerves of local residents, who wonder if their lives will ever return to normal.
"Everybody is so stressed here. We're just sitting here waiting and they're not telling us anything because they don't know. I had four people who came yesterday crying," said Grand Isle restaurant owner Annette Rigaud, who may be forced to close down.
BP's chief operating officer Doug Suttles acknowledged that until the cap is in place the flow of oil into the Gulf would likely increase by as much as 20 percent.
The US government, which has launched a criminal investigation into the disaster, has estimated the flow of oil before the riser was cut away at 12,000 to 19,000 barrels a day -- meaning at least 20 million gallons have already poured into the Gulf since April.
As pressure mounted on BP and its stock price plummeted, the Coast Guard said BP has been ordered to cover the cost of constructing five additional barrier islands off the Louisiana coast to prevent oil from making landfall.
That would mean a total of six barrier islands in all to surround the most vulnerable shorelines "as part of our continuing commitment to do everything possible to protect our vital coastal communities," Coast Guard official Allen said.
Under-fire BP chief executive Tony Hayward also apologized for saying in an interview that he would "like my life back."
"I made a hurtful and thoughtless comment on Sunday when I said that 'I wanted my life back,'" Hayward said in a post to BP America's Facebook page.
"When I read that recently, I was appalled. I apologize, especially to the families of the 11 men who lost their lives in this tragic accident," he said.
