By Steve Gelsi, MarketWatch
NEW YORK (MarketWatch) -- Emergency crews along the Gulf of Mexico bolstered shoreline defenses Wednesday to fend off a fast-spreading oil slick that the U.S. Coast Guard warned will wash into Louisiana delta marshes by the weekend and could soon threaten the beaches of western Florida.
Exactly when or where the oil might hit the Sunshine State is hard to say, but authorities signaled they're stepping up spill impact response measures in the Florida Keys and the west coast of Florida, including St. Petersburg.
"We're in the planning stages, just setting up with local and state agencies, so we can put people into action," Petty Officer Mariana O'Leary said from St. Petersburg, where the Coast Guard set up a new unified command center with state, federal and county agencies. "More people are coming in to get ready."
Meanwhile, brown crude, gushing now for two weeks from an uncapped BP PLC /quotes/comstock/13*!bp/quotes/nls/bp (BP 50.33, -0.66, -1.29%) well, stretches across 120 miles of ocean south of Louisiana in what is now the worst offshore oil-well blowout since the 1969 Santa Barbara Channel spill.
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Taking aim at the looming emergency, Florida Gov. Charlie Crist said the state faces an "underground volcano of oil" that threatens the region's ample fishing and travel industries.
BP said a hastily constructed 40-foot steel containment dome is due to leave Port Fourchon, La., for deployment at the site of the leak, about 41 miles offshore on Mississippi Canyon block 252.
If all goes according to plan, the device could be on site by Friday where it will be lowered 5,000 feet and funnel escaping oil up to a standby surface vessel. The technique has been used in shallow water but never at these depths.
"The plan is to catch the oil as it leaks," said BP spokesman Toby Odone.
Meanwhile, the spill continues to grow, perhaps at a rate faster than previously assumed. BP officials the well could spew as much as 60,000 barrels of crude a day into the sea, 12 times more than the current estimate of 5,000 barrels a day.
"If all of the equipment present were to be removed, the rate could go up to that rate," said BP Chief Operating Officer Doug Suttles, who appeared at a press briefing. He said the leak is not at that elevated level, "but it's not impossible" that it could worsen.
Oceanographers are now raising the possibility the slick could be swept up in the Loop Current, which runs along Florida and into the Atlantic.
The floating crude remains off the coast of Louisiana for now, as the spill moved into its third week since a BP-leased drill rig exploded on April 20 and sank two days later -- on Earth Day.
Based on the latest projections from the National Oceanic and Atmospheric Administration, the slick will surround the toe of Louisiana by Friday, and drift further west in the Gulf of Mexico.
Winds are expected to be light and variable through Wednesday. The shorelines of the Mississippi Delta, Breton Sound and Chandeleur Sound continue to be threatened by the slick through the forecast period, NOAA said.
Robert Weisberg, a physical oceanographer at the University of South Florida, told reporters on a conference call Wednesday that the powerful Loop Current that sweeps around the Gulf may soon make contact with the oil slick.
