BATON ROUGE, La. - Travis Morace has been running boats on the Mississippi for two decades, witnessing all of the mighty river's many moods. He's seen it calm and smooth as a newly paved road and endured jarring rides filled with treacherous twists and bumps.

But even experienced river pilots have never seen anything like the roiling current now racing to the Gulf of Mexico. Since spring floods pushed the Mississippi to historic heights, America's busiest inland waterway has become one of its most challenging to navigate.

"If you're not scared of it, you should be, because it has a lot of ways of hurting you," Morace said this week as he slowly nudged his tugboat, the Bettye M. Jenkins, along the river bank near Vidalia, La.

The high water brings with it a host of hazards. Debris is everywhere, and the unusually swift current makes it difficult for pilots to go upstream. Good luck stopping if you're headed downstream. For those who make their living on the water, the river is a respected adversary in the best of times. Now it just plain frightens them.

On Friday, the Mississippi at Vidalia looked more like a stormy ocean than a river. Whitecaps frothed under the bridge that connects the city to Natchez, Miss., and whirlpools churned across the channel.

In many places, obstacles were hiding just beneath the surface. Some trees in Natchez were nearly submerged. A basketball hoop protruded about 2 feet above the water at a flooded-out court.

The current was filled with flotsam of every sort, including whole trees and long, green ribbons of vegetation. A nearby alligator struggled against the water's pull, finally finding refuge on the porch of a building partly concealed by the rising water.

The high water and rapid current caused at least two barges to break loose from a towboat Friday and hit a bridge. Three barges of corn sank, the towboat's owner said. No one was hurt.

The barges went down near Baton Rouge, prompting the Coast Guard to close a five-mile stretch of the river. Officials did not know when it would reopen.

Earlier in the week, the Coast Guard briefly closed a 15-mile span of the river near Natchez because of the current and concerns that the wakes from passing vessels would put pressure on floodwalls protecting communities. The wakes were also washing floodwater into some businesses.

Although the river was soon reopened near Natchez, barge and tug traffic is still being tightly regulated.

The Coast Guard normally asks vessels to maintain a minimum speed of 3 mph going upstream. But these days, they can go only about 1 mph to avoid generating wakes. When heading south, many have trouble stopping in the fast current.

"You ask me, they should close it down altogether," said Jerry Batson, captain of the tug Gladys Batson. "It's awful risky for any vessel."

On Wednesday, Batson watched as a boat pushing two empty chemical barges stalled while trying to pass under the Vidalia-Natchez bridge.

"It almost hit the bridge backing up," he said.

Before the river began to flood, the Gladys Batson routinely pushed four, 200-foot barges at a time. But the current now makes it hard to steer or to move that much cargo.

Farther south in Louisiana, the high water also presents a challenge to pilots who guide oceangoing vessels into ports from New Orleans to Baton Rouge.

Michael Lorino, head of the Associated Branch Pilots, said pilots have to maneuver through tricky currents made worse by the river's many bends, and they must stay away from sandbars built by the huge amount of silt carried down during high-water season, usually in the spring.

They have to learn, and re-learn, the river every day, all while dodging towboats, cruise liners, ferries and massive grain and chemical ships.

Bill Wilson, whose company carries about 300,000 passengers a year on its Natchez steamboat in New Orleans, said his captains have a good relationship with river pilots and work together to stay safe, especially when the water is high.

"We pretty much stay out their way. They're the big guys," said Wilson, vice president and general manager of the New Orleans Steamboat Co.

Many ships entering the river are bound for the Port of South Louisiana, which lines both sides of the Mississippi north of New Orleans. It's the nation's largest port in terms of tonnage, and it handles more than half of American grain exports.

Barges travel from farm country down the Missouri, Ohio and Mississippi rivers. When they get to the port, the crops are put aboard massive grain carriers for shipment overseas. Or the grain is put into tall elevators to await later shipment.

The port handles about 60,000 barges a year, along with 4,500 to 5,000 deep-draft vessels.

That kind of commercial traffic means closing the river is costly. Huge ships waiting to take on cargo can run up expenses of $40,000 a day. Port officials say the total cost of a single day's closing can top $300 million.

When the water began to climb, the shipping industry was one of the biggest proponents of opening spillways to divert excess water from the Mississippi. The Army Corps of Engineers first opened the Bonnet Carre spillway north of New Orleans, then the Morganza spillway north of Baton Rouge.

Those actions helped keep ports open and eased pressure on the levees protecting Baton Rouge and New Orleans.

Ports downstream are still open until the surge of water arrives. But in Vidalia, about 140 miles upriver from New Orleans, a lot of business has come to a halt. The river crested in that area Friday at nearly 14 feet above flood stage, a level that was lower than first predicted but about three feet higher than the 1937 record.

Forecasters said it could be days before the water begins to recede.

Carla Jenkins, whose family has been in the towing business for generations, said her boats stopped accepting work orders Tuesday. And at a spot where barges are usually tied up, brown river water sweeps over three buoys in the river. The barges are gone.

"I told everyone to come and get them," she said. "I couldn't guarantee they would be safe now. I've never seen anything like this and never hope to again."

Her offices, built between the river and the levee and standing atop 10-foot pilings, now have several feet of water in them.

The river has torn off the steps and swept away the wheelchair ramp. Acres of land where she stores limestone gravel are now beneath as much as 30 feet of water. She estimates she's losing $70,000 to $80,000 a week in towing alone - in addition to losses from the gravel business.

For a small operator like Batson, the flood could be financially devastating, but he insists he won't venture onto the Mississippi until it quiets down.

"You couldn't whip me and make me go out there now," he said.