A boat uses a boom and absorbent material to soak up oil in Cat Bay, near Grand Isle, La., on June 28. A tropical storm is expected to hit the Gulf and impede cleanup efforts.
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Florida Gov. Charlie Crist and wife Carole Rome Crist (right) stand with others during a Hands Across the Sand event June 26 in Pensacola, Fla. The event was staged across the nation to protest offshore oil drilling.
Joe Raedle/Getty Images
Oil clouds the surface of Barataria Bay near Port Sulpher, La., on June 19.
Sean Gardner/Getty Images
Workers adjust piping while drilling a relief well at the site of the Deepwater Horizon oil spill.
Charlie Neibergall/Getty Images
A dolphin rises up out of the water near Grand Terre Island off the coast of Louisiana on June 14.
Derick E. Hingle/AP
President Obama stands with Mississippi Gov. Haley Barbour (right) and Gulfport, Miss., Mayor George Schloegel after meeting with residents affected by the oil spill.
Crude oil washes ashore in Orange Beach, Ala., on June 12. Oil slicks, 4 to 6 inches thick in some parts, have washed up along the Alabama coast.
A volunteer uses a toothbrush to clean an oil-covered white pelican at the Fort Jackson Oiled Wildlife Rehabilitation Center in Buras, La., June 9.
Saul Loeb/AFP/Getty Images
A shrimp boat skims oil from the surface of the water just off Orange Beach, Ala., as a family enjoys the surf. Oily tar balls have started washing up on Orange Beach and beaches in the western Florida panhandle.
Sand from a dredge is pumped onto East Grand Terre Island, La., to provide a barrier against the Deepwater Horizon oil spill, June 8.
A dead turtle floats on a pool of oil from the Deepwater Horizon spill in Barataria Bay off the coast of Louisiana on June 7.
Workers use absorbent pads to remove oil that has washed ashore from the spill in Grand Isle, La., June 6.
Plaquemines Parish coastal zone director P.J. Hahn lifts an oil-covered pelican out of the water on Queen Bess Island in Plaquemines Parish, La., June 5.
Heavy oil pools along the side of a boom just outside Cat Island in Grand Isle, La., June 6.
Win McNamee/Getty Images
President Obama walks alongside Grand Isle Mayor David Camardelle (from right), U.S. Coast Guard Adm. Thad Allen, who is in charge of the federal response to the spill, and Chris Camardelle after meeting with local business owners in Grand Isle, La., June 4.
Saul Loeb/AFP/Getty Images
A brown pelican sits on the beach at East Grand Terre Island along the Louisiana coast after being drenched in oil from the BP Deepwater Horizon oil spill, June 3.
U.S. Attorney General Eric Holder announces that the Justice Department has launched a criminal investigation into the BP oil spill. With him, from left: Stephanie Finley and Jim Letten, U.S. attorneys for the Western District of Louisiana; Ignacia Moreno, assistant attorney general for the Environment and Natural Resources Division; Tony West, assistant attorney general, Civil Division; and Don Burkhalter, U.S. attorney for the Southern District of Mississippi.
The oil slick off the coast of Louisiana, seen from above.
NASA via Getty Images
A worker leaves the beach in Grand Isle, La., on May 30. BP is turning to yet another mix of undersea robot maneuvers to help keep more crude oil from flowing into the Gulf.
Jae C. Hong/AP
Protesters cover themselves with a water and paint mixture during a demonstration at a BP gas station in New York City on May 28.
Workers clean up oil in Pass a Loutre, La. The latest attempt to plug the leak was unsuccessful.
Jae C. Hong, File/AP
Residents listen to a discussion with parish officials and a BP representative on May 25 in Chalmette, La. Officials now say that it may be impossible to clean the hundreds of miles of coastal wetlands affected by the massive oil spill.
Sean Gardner/Getty Images
An oil-soaked pelican takes flight after Louisiana Fish and Wildlife employees tried to corral it on an island in Barataria Bay on the coast of Louisiana. The island, which is home to hundreds of brown pelican nests as well at terns, gulls and roseate spoonbills, is impacted by oil from the Deepwater Horizon spill.
A sign warns the public to stay away from the beach on Grand Isle, La. Officials closed the oil-covered beaches to the public indefinitely on Saturday.
John Moore/Getty Images
Pelican eggs stained with oil sit in a nest on an island in Barataria Bay on May 22.
A bird flies over oil that has collected on wetlands on Elmer's Island in Grand Isle, La., May 20. The oil came inland despite oil booms that were placed at the wetlands' mouth on the Gulf of Mexico.
Members of the Louisiana National Guard build a land bridge at the mouth of wetlands on Elmer's Island.
The hands of boat captain Preston Morris are covered in oil after collecting surface samples from the marsh of Pass a Loutre, La., on May 19.
Louisiana Gov. Bobby Jindal (center) and Plaquemines Parish President Billy Nungesser (right) tour the oil-impacted marsh of Pass a Loutre, La. "This is the heavy oil that everyone's been fearing that is here now," said Jindal.
BP Chairman and President Lamar McKay (left), with Transocean President and CEO Steven Newman (center) and Applied Science Associates Principal Deborah French McCay, testifies during a Senate Committee on Commerce, Science, and Transportation hearing May 18 on response efforts to the Gulf Coast oil spill.
Manuel Balce Ceneta/AP
This undated frame grab image received from BP and provided by the Senate Environment and Public Works Committee shows details of the oil spill in the Gulf of Mexico. BP has agreed to display a live video feed of the oil gusher on the Select Committee on Energy Independence and Global Warming Committee's website beginning Thursday evening.
Senate Environment and Public Works Committee/AP
President Obama speaks with local fishermen about how they are affected by the oil spill in Venice, La., on May 2.
Saul Loeb/AFP/Getty Images
Danene Birtell with Tri-State Bird Rescue and Research tends to a Northern Gannet in Fort Jackson, La., on April 30. The bird, normally white when full grown, is covered in oil from the oil spill.
Since the explosion, a third oil leak has been discovered in the blown-out well.
In this aerial photo taken April 21 more than 50 miles southeast of Venice, La., the Deepwater Horizon oil rig burns.
Tendrils of oil mar the waters of the Gulf of Mexico in this satellite image taken Monday. An estimated 5,000 barrels of oil a day are seeping into the Gulf, after an explosion last week on a drilling rig about 50 miles off the Louisiana coast.
Courtesy of Digital Globe
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A ship carrying a 100-ton containment box is heading to an oil leak site in the Gulf of Mexico to try to cover the flow of crude and funnel it to a tanker.
The captain said the ship was on its way early Wednesday evening and is headed about 50 miles off the Louisiana coast. The contraption will then be lowered about 5,000-feet below the water's surface.
It will be the first time the use of such a system has been attempted at this depth.
The concrete-and-steel structure is 40-feet tall and will be outfitted with valves and pipes that will carry the crude into a
Oil company BP hopes the contraption can be on the seabed in the next two days, and that it will be able to hook up the device over the weekend.
Earlier, BP used remotely operated vehicles a mile below the surface of the water to cut off a section of pipe that used to lead from the well up to an oil rig that exploded last month, killing 11 workers. After cutting off the section of pipe, BP capped it with a valve.
The National Oceanic and Atmospheric Administration says that while this stopped one of three leaks, oil is still flowing into the Gulf at a rate of 210,000 gallons a day.
BP is trying to reduce the number of leak points as it deploys the 100-ton box.
Interior Secretary Ken Salazar inspected the site by helicopter and told reporters the strategy "limits the need for the containment effort that BP is undertaking." He said federal officials have inspected 30 Gulf oil rigs to look for problems that could lead to another spill, but so far no significant problems have been identified.
The U.S. State Department said officials are considering offers of assistance from 13 countries and the United Nations. Canada and Mexico are among those offering equipment and experts. Also offering aid are Britain, Croatia, France, Germany, Ireland, the Netherlands, Norway, Romania, South Korea, Spain, Sweden and the U.N. Environmental Program.
Meanwhile, the effort to protect Louisiana's coastal wetlands was expected to pick up.
In Plaquemines Parish, officials loaded absorbent booms shortly after dawn to take out to the mouth of the Mississippi River. The barge will be used as a distribution point for local fishermen to lay the booms around sensitive marshes.
At a nearby marina, local shrimpers planned to use their boats to put down booms as part of a program BP is running.
Also Wednesday, federal fisheries officials were investigating whether aggressive shrimpers were causing the deaths of endangered sea turtles that have been washing up on Gulf Coast beaches with no signs of oil, an official told The Associated Press.
Investigators will look at whether some shrimp boats taking part in an emergency shrimping season ahead of the Gulf oil spill removed devices from their nets that are intended to allow turtles to escape, said Sheryan Epperly, sea turtle team leader for the National Marine Fisheries Service.
Wildlife officials say at least 35 endangered sea turtles have washed up on Gulf Coast beaches, but it's not clear what's killing them. Necropsies have shown no signs of oil.
In all, about 7,900 people are working to protect the shoreline and wildlife, and some 170 boats are also helping with the cleanup.
A rainbow sheen of oil has reached land in parts of Louisiana, but forecasts showed that the oil wasn't expected to come ashore for at least a couple more days.
"It's a gift of a little bit of time. I'm not resting," U.S. Coast Guard Rear Adm. Mary Landry said.
Still, some satellite images indicated signs of oil near the mouth of the Mississippi River.
In their worst-case scenario, BP executives told members of a congressional committee that up to 2.5 million gallons a day could spill if the leaks worsened, though it would be more like 1.7 million gallons. In an exploration plan filed with the government in February 2009, BP said it could handle a "worst-case scenario" it described as a leak of 6.8 million gallons per day from an uncontrolled blowout.
Containment boxes have never been tried at this depth — about 5,000 feet — because of the extreme water pressure. If all goes well, the contraption could be fired up early next week to start funneling the oil into a tanker.
"We don't know for sure" whether the equipment will work, Salvin said. "What we do know is that we have done extensive engineering and modeling, and we believe this gives us the best chance to contain the oil, and that's very important to us."
The Deepwater Horizon rig was owned by Transocean Ltd. Some of the 115 surviving workers who were aboard when it exploded are suing that company and BP. In lawsuits filed Tuesday, three workers say they were kept floating at sea for more than 10 hours while the rig burned uncontrollably. They are seeking damages.
Guy Cantwell, a spokesman for Transocean Ltd., defended the company's response, saying 115 workers did get off alive. Two wrongful death suits also have been filed.
Also, the Associated Press reported Wednesday that the federal Minerals Management Service, which regulates offshore oil rigs, changed its rules two years ago, allowing BP to avoid filing a plan specifically for handling a major spill from an uncontrolled blowout at its Deepwater Horizon project — exactly the kind of disaster now unfolding in the Gulf of Mexico.
Oil rig operators generally are required to submit a detailed "blowout scenario," But the MMS issued a notice in 2008 that exempted some drilling projects in the Gulf under certain conditions. BP met those conditions, according to MMS, and as a result, the oil company had no plan written specifically for the Deepwater Horizon project.
Meanwhile, as officials work on cleanup, the long wait is taking its toll on nerves and incomes.
At the Port Of New Orleans, there are worries that ships covered in oil might pollute the river. Spokesman Chris Bonura said the Coast Guard is inspecting ships at sea, before they enter the mouth of the Mississippi.
"What they have done is they have established a couple of cleaning stations," he said. "And what the Coast Guard have been watching is if a ship is going through an oil sheen is then transferring that sheen into clean water."
So far, no ships have required cleaning.
In Gulf Shores, Ala., the real estate firm Brett/Robinson Vacations sent a note to those renting vacation properties that they would not be penalized for any spill-related cancellations but urged them not to jump the gun.
"There are many questions and many 'what ifs' regarding this event," the message read. "Because changes come about hourly and 30 days is a long way away, we are asking you to wait before canceling your vacation, especially those of you who are scheduled to arrive more than 30 days from today."
There are legitimate concerns, experts say. A brown pelican found in the slick is recovering at a bird rescue center in Louisiana. National Wildlife Federation President and CEO Larry Schweiger says there's no way to know how many birds have been oiled because the slick is so big and so far offshore.
Michael Seymour, a bird expert with Louisiana's Department of Wildlife and Fisheries, told NPR's Michele Norris that volunteers are working to fix the birds' feathers.
"Once their feathers have been structurally repaired through preening, then they'll be more waterproof, they'll be a little more weatherproof and it'll help stabilize their temperature as well," Seymour said. "It's critical that they get their feathers back to normal."
He said the department is trying to determine what to do with the birds that have been rehabbed but was optimistic about their future. "The success rate of releasing birds after they have been rehabbed is on the order of 80 percent," Seymour said. "So that's good news."
Perdido Key, a barrier island between Pensacola and the Alabama state line with sugar-white sand studded with condominiums, very likely would be the first place in Florida affected by the oil spill. Perdido — Spanish for "Lost" — got a sniff Tuesday morning of what may be in store.
"You could smell the smell of it, real heavy petroleum base," said Steve Owensby, 54, a maintenance man at the Flora-Bama Lounge abutting the state line on the Florida side.
The air cleared later, but Owensby's 28-year-old daughter, Stephanie, who tends bar at the lounge, said some visitors have complained of feeling ill from the fumes.
"It's very sad because I grew up out here," she said. "I remember growing up seeing the white beaches my whole life. Every day I've been going to the beach ... a lot of people are out watching and crying."
Contributing: NPR's Larry Abramson, Jeff Brady and Debbie Elliott. Material from The Associated Press was also used in this report.