HATTERAS, N.C. » Evacuations began on a tiny barrier island off North Carolina as Hurricane Irene strengthened to a major Category 3 storm over the Bahamas on Wednesday with the East Coast in its sights.

Irene’s maximum sustained winds increased to near 115 mph with additional strengthening forecast, the U.S. National Hurricane Center in Miami said.

The evacuation in North Carolina was a test of whether people in the crosshairs of the first major hurricane along the East Coast in years would heed orders to get out of the way.

The first ferry to leave Ocracoke Island arrived just before 5:30 a.m. in nearby Hatteras with around a dozen cars on board.

It won’t be easy to get thousands of people off Ocracoke Island, which is accessible only by boat. The 16-mile-long barrier island is home to about 800 year-round residents and a tourist population that swells into the thousands when vacationers rent rooms and cottages. Tourists were told to evacuate Wednesday. Island residents were told to get out on Thursday.

It wasn’t clear how many people on the first arriving ferry Wednesday morning were tourists, but the first two cars to drive off it had New York and New Jersey plates.

Getting off the next ferry about an hour later was a family that included newlywed Jennifer Baharek, 23, of Torrington, Conn. She and her husband, Andrew, were married Monday and planned to spend their honeymoon on the island.

"We just got to spend one day on the beach and then we went to bed early to get up for the evacuation," she said.

Federal officials have warned Irene could cause flooding, power outages or worse all along the East Coast as far north as Maine, even if it stays offshore. The projected path has gradually shifted to the east, though Irene is still expected to make landfall as a major hurricane in North Carolina sometime over the weekend. It is then expected to continue trudging northward.

Speaking Wednesday on ABC’s "Good Morning America," Craig Fugate, head of the Federal Emergency Management Agency, said people as far north as New England should be ready for the storm. When asked about concerns preparing the Northeast for a hurricane, which is uncommon in that part of the country, Fugate cited Tuesday’s earthquake that rattled the East Coast.

"It’s a reminder that we don’t always get to pick the next disaster," Fugate said.

In North Carolina, the state-run ferry service off Ocracoke Island would be free during the evacuation, but no reservations were allowed. Boats can carry no more than 50 vehicles at a time.

The island is part of North Carolina’s Outer Banks, a roughly 200-mile stretch of fragile barrier islands off the state’s coast. Pristine beaches and wild mustangs attract thousands of tourists each year. Aside from Ocracoke, the other islands are accessible by bridges to the mainland and ferries. The limited access can make the evacuation particularly tense.

All the barrier islands have the geographic weakness of jutting out into the Atlantic like the side-view mirror of a car, a location that’s frequently been in the path of destructive storms over the decades.

Many remember 1999’s Hurricane Floyd, which made landfall as a Category 2 and caused a storm surge that wiped out scores of houses and other properties on the Outer Banks.

As of 8 a.m. EDT Wednesday, Irene was centered about 335 miles (540 kilometers) southeast of Nassau in the Bahamas and was moving west-northwest near 9 mph (15 kph).

It had already wrought destruction across the Caribbean, giving a glimpse of what the storm might bring to the Eastern Seaboard. In Puerto Rico, more than a million people were without power, and one woman died after trying to cross a swollen river in her car. At least hundreds were displaced by flooding in the Dominican Republic, forced to take refuge in schools and churches.

Forecasters warned it could get worse: The storm was likely to strengthen into a Category 4 monster by the time it makes landfall in the U.S. this weekend. Irene could crawl up the coast Sunday toward the Northeast region, where residents aren’t accustomed to such storms.

It’s been more seven years since a major hurricane, considered a Category 3 with winds of at least 111 mph (179 kph), hit the East Coast. Hurricane Jeanne came ashore on Florida’s east coast in 2004.

On North Carolina’s mainland, residents who have weathered years of storms took notice. People flocked to gas stations and stores to stock up on supplies like gasoline for generators, plywood for boarding up windows, flashlights, batteries and drinking water.

In the coastal city of Wilmington, Tommy Early watched Tuesday as customers came in to his Shell service station to prepare. Irene was the main topic of conversation there, and Early was getting ready to give the hurricane its rightful place in a thick yellow notebook, even if it takes a turn out to sea. For years, Early has tracked names, wind speeds, rainfall and other data from storms that are nearly as familiar there as beach-loving tourists.

"Hurricane Earl," Early said Tuesday, looking up the entry for the storm that narrowly missed North Carolina last year. Evacuations also were ordered last year ahead of Earl. "That was a Category 4 at one point. One hundred and sixty-mile-an hour winds. We got lucky that time."

The last hurricane to hit the U.S. was Ike in 2008. The last Category 3 or higher to hit the Carolinas was Bonnie in 1998, but caused less damage than other memorable hurricanes: Hugo in 1989, Floyd in 1999 and Isabel in 2003.

Though a Category 2, Isabel cut a new inlet through Hatteras Island and killed 33 people.

At Craft American Hardware at Wrightsville Beach, Don Korman said he had placed a big order set to arrive Wednesday: Batteries, lanterns, tarps and shutter supplies.

"People are watching the TV, but they usually come by a few days before," he said. "If it looks like it’s coming like this, you can run out of stock really quick."

Korman, though, plans to be ready even for 11th-hour supply trips: the store is ready to plywood its windows and run off generator power until it becomes unsafe or unwise to keep the doors open.

"We won’t close until the last minute," he said.

Most locals were heeding the warnings and getting ready for the storm, though few seemed panicked.

"Water, batteries, flashlights and now I’m going to get my grocery shopping done," said Sally Godwin, carrying two large jugs of fresh water out of Korman’s store with her. "I live at the beach, and they always evacuate it the day before. I have to make sure all my little stuff’s taken care of."