NEW YORK (CNNMoney.com) -- Oil from a leaking well beneath the sunken rig in the Gulf of Mexico continued to pour into the water Tuesday, according to the Coast Guard.
The slick is located about 36 miles from the Louisiana coast. An estimated 42,000 gallons of oil a day continues to leak from the open well.
On Tuesday, the Coast Guard said the spill, measured from end to end, stretched as wide as 42 miles by 80 miles, although oil isn't necessarily covering that entire area.
Most of the slick is a thin sheen on the water's surface. About 3% of it is a heavy, pudding-like crude oil.
On Monday the spill ranged over an area roughly 42 by 33 miles. The Coast Guard said the spill wasn't necessarily getting larger in size, but rather changing in shape due wind, tides and other factors.
The ongoing leak might be offset by response vessels that are corralling the thick crude oil with containment booms and skimming some of oil off the surface.
The spill has the potential to be a major disaster if left unchecked, although at its current flow rate would take over 260 days to rival the Exxon Valdez disaster, which discharged some 11 million gallons into Alaska's Price William Sound.
Still, the Coast Guard said it is preparing for the worst.
"We're working hard to make sure we don't have a very serious spill," Coast Guard Rear Admiral Mary Landry said at a press conference Monday afternoon. "We're not abandoning this response posture until this well is completely secured."
The Coast Guard, BP, and the rig's owner Transocean (RIG), have deployed nearly 50 vessels to help contain and clean the slick.
Marine life has been spotted in the area. Over the weekend a plane from the U.S. Fish and Wildlife Service sighted five small whales nearby. Crews working to contain the spill were alerted to their presence.
Efforts are also underway near the shoreline to deal with the spill should it reach land, including positioning boom material around sensitive ecological areas.
Five staging areas have been set up on land, stretching from Venice, La. to Pensacola, Fla.
Landry said it appears the slick will remain at sea for at least the next three days. That could change if the wind shifts.
The oil, if it stays at sea, will eventually evaporate, breakdown and sink, or get cleaned up.
But analysts have said the spill could have political fallout, especially if it reaches shore.
Several lawmakers and interest groups have led a charge over the last several years to open up more parts of the U.S. coast for oil drilling, efforts that are generally supported by the public.
That support could erode if crude oil starts washing up on the Louisiana or Mississippi coasts.
The well is expected to continue leaking until it is sealed. The leak appears to be coming from a pipe that ran from the well head to the drilling rig, which is now laying upside down in 5,000 feet of water not far from the well head.
It has not been decided if the rig will be salvaged or remain where it is, a Transocean official said Monday.
To seal the leak, three approaches are being tried.
BP is now using a set of remote controlled submarines in an attempt to activate the well's "blow out preventer" -- a steel device the size of a small house that sits atop the well and is intended to choke off the flow of oil in the event of a disaster.
It's not clear why that device didn't not originally act to cap the well, or if it will be of any use going forward.
BP is also bringing in another drilling rig which could seal the well, but that effort will take months, according to a BP spokesman.
In the meantime, the company is also trying a novel approach to capture the oil -- using a dome right above the well head. The dome resembles an inverted funnel, with a pipe leading up to ships waiting at the surface to capture the oil. That tactic has never been tried in water this deep.
A BP spokesman said the dome might be ready in a few weeks.
The blast last week, which is still under investigation, resulted in 11 workers going missing. The search for them was suspended last Friday.
Fed Chair Janet Yellen's testimony highlighted concerns about the most recent volatility in global markets as well as the economy's gains. More
Digital, instant and on-demand. That's how we get our movies, travel arrangements, and even bills. Why not our paychecks? More
Instead of asking how long your savings will last, ask how long you should plan for your nest egg to last so it can support you throughout retirement. More