BOSTON — With the projected path of Hurricane Earl moving closer to Nantucket, island officials are recommending that people stay off the beaches, move their boats and close shutters.

“We’re preparing for the worst,” assistant town manager Gregg Tivnan said today.

The National Hurricane Center in Miami today issued a hurricane warning for the Massachusetts coast from Westport to Hull, including Cape Cod and the Islands, with Nantucket expected to be the hardest hit.

A tropical storm warning is in effect from New Haven, Conn., to Westport, Mass., including Block Island, R.I.

A tropical storm watch is in effect from Hull, Mass., to Eastport, Maine.

Currently a Category 4 storm, Earl is expected to weaken to a Category 2 by the time it reaches New England on Friday night.

Earl was about 750 miles south-southwest of Nantucket late this morning, and moving due north at 18 mph.

The National Weather Service is predicting winds gusts up to 85 mph for Cape Cod, and gusts of more than 100 mph on Nantucket.

The good news is there’s not expected to be any significant storm surge, said Charlie Foley, a meteorologist with the National Weather Service.

“The main impact would be high surf, dangerous rips, heavy rain and wind,” he said.

Nantucket closed all public beaches at noon today ahead of the storm, meaning lifeguards would not be on duty. The island’s emergency shelter at the high school was scheduled to open Friday.

“We’re recommending people not go in the water,” Tivnan said. “In fact, we’re encouraging people not to even go on the beaches on the southern parts of the island. One wave is all it takes to sweep someone away.”

Tivnan recommends that residents with storm shutters use them, and board up windows if they don’t have shutters. Some town-owned buildings are being boarded.

There has already been a steady exodus of boats, and those that remain are being “spider moored,” meaning they are all tied together.

Mariners were hauling boats on Nantucket and elsewhere.

Clayton Smith and his colleagues at Yachting Solutions were scrambling to get boats to safety. He said his Rockport, Maine-based company was being aggressive even though the hurricane’s precise path was uncertain. They planned to pull 40 boats from the water in 48 hours.

“Complacency is a bad thing. It’s better to be safe than sorry,” he said.

Arno’s Main Street Grill on Nantucket plans on staying open Friday, barring a power outage or a state of emergency declaration by the governor, owner Chris Morris said.

The restaurant hasn’t had any canceled reservations, although some people have requested moving their reservations from Friday to Thursday, he said.

The hurricane may even be good for business. “There’s not much else to do during a hurricane besides eat and drink,” he said. “I mean, there’s only so many times you can visit the whaling museum.”

State campgrounds on the Cape and along the South Coast are closing today, shelters are being prepared and state police have moved barriers into place in case the region’s emergency traffic plan takes effect.

The Army Corps of Engineers, which oversees the two bridges connecting Cape Cod to the mainland, said the spans close when sustained winds reach 70 mph because they become too dangerous for traffic.

The state’s Emergency Management Agency is prepared to send supplies to any shelters that open on the Cape, but so far have not had any requests, spokesman Peter Judge said.