RALEIGH, N.C. — Powerful Hurricane Earl wheeled toward the East Coast, driving the first tourists Wednesday from North Carolina vacation islands and threatening damaging winds and waves up the Atlantic seaboard over Labor Day weekend.

Visitors were taking ferries off Ocracoke Island and told to leave neighboring Cape Hatteras in North Carolina’s Outer Banks, and federal authorities have warned people all along the Eastern seaboard to be prepared to evacuate.

Virginia’s Gov. Bob McDonnell declared a state of emergency as a precaution, allowing the state to position staff and resources ahead of the storm. Emergency officials as far north as Maine urged people to have disaster plans and supplies ready.

Earl was still more than 700 miles south-southeast of Cape Hatteras, with top sustained winds of 125 mph. It was on track to near the North Carolina shore late Thursday or early Friday and then blow north along the coast, with forecasters cautioning that it was still too early to tell how close the storm may come to land.

The National Weather Service issued a hurricane warning for much of the North Carolina coast and hurricane watches from Virginia to Delaware.

Not since Hurricane Bob in 1991 has such a powerful storm had such a large swath of the East Coast in its sights, said Dennis Feltgen, spokesman for the National Hurricane Center.

“A slight shift of that track to the west is going to impact a great deal of real estate with potential hurricane-force winds,” Feltgen said.

Even if Earl stays well offshore, it will kick up rough surf and dangerous rip currents up and down the coast through the Labor Day weekend, a prime time for beach vacations, forecasters said.

The only evacuation orders so far affected parts of the Outer Banks, thin strips of beach and land that face the open Atlantic.

Tourist cars, some with campers in tow, lined up for the first ferries of the day from Ocracoke to the mainland. Another car ferry connects to Hatteras, which has a bridge to the mainland and came under the second evacuation order a little later Wednesday morning.

The evacuation orders are called mandatory, but Julia Jarema, spokeswoman for the state Division of Emergency Management, said it doesn’t mean people will be forced from their homes. Local law enforcement officials may do something such as going door-to-door and asking people who stay behind for their information about their next of kin.

Emergency officials said they hoped Ocracoke’s 800 or so year-round residents would heed the call to leave. But Carol Paul said she and husband Tom would stay put if the current forecasts hold. Only a direct hit from a stronger storm would drive them from the island where they’ve lived for seven years, running an antiques store.

“There’s never been a death on Ocracoke from a hurricane, so we feel pretty comfortable,” Carol Paul 57, said as tourists departed on ferries and her husband, also a construction contractor, worked to board up the windows of clients and friends’ homes. “Everything here is made pretty much with hurricanes in mind.”

The approaching storm troubled many East Coast beach towns that had hoped to capitalize on the BP oil spill and draw visitors who normally vacation on the Gulf Coast.

Carl Hanes of Newport News, Va., kept an eye on the weather report as he headed for the beach near his rented vacation home in Avon, N.C. He, his wife and their two teenage children were anticipating Earl might force them to leave on Thursday, a day ahead of schedule.

“We’re trying not to let it bother us,” Hanes said before enjoying the calm surf.

In Rehoboth Beach, Del., Judy Rice said she has no plans to leave the vacation home where she has spent most of the summer. In fact, the Oak Hill, Va., resident plans to walk around town in the rain if it comes.

“I kind of enjoy it actually. You know, it’s battling the elements,” Rice said. “I have seen the rain go sideways, and, yeah, it can be scary, but I have an old house here in Rehoboth, so it’s probably more important that I am here during a storm than anywhere.”

In the Florida Panhandle, which has struggled all summer to coax back tourists scared away by the Gulf oil spill, bookings were up 12 percent over last year at the Sandestin Golf and Beach Resort. The resort is nowhere near Earl’s projected path, and spokeswoman Laurie Hobbs said she suspects the increase in reservations was partly because of a discount the hotel is offering and partly because of the hurricane.

“Weather drives business,” she said. “They go to where the weather is best.”

If Earl brings rain farther inland, it could affect the U.S. Open tennis tournament, being played now through Sept. 12 in New York City.

“We’re keeping our eye on it very closely,” said United States Tennis Association spokesman Chris Widmaier.