MIAMI (AP) _ Hurricane Fran roared along at 115 mph Tuesday night and its winds were expected to get even stronger as it aimed to make landfall along the southeastern U.S. coast late Thursday.

A hurricane watch, meaning the storm could hit within 36 hours, could go up for Georgia and South Carolina by Wednesday morning, meteorologist Robert Molleda said Tuesday night at the National Hurricane Center.

Much of the Bahamas, a mecca for American gamblers and other vacationers, was bracing for a possible hit even though it appeared that Fran would pass north of the islands.

Heading west-northwest at 13 mph, Fran was expected to take a gradual turn to the northwest by early Wednesday, Molleda said.

``That would take it into either Georgia or South Carolina sometime Thursday night,'' he said.

Fran's winds jumped quickly from 85 mph early Tuesday to 115 mph, making it a Category 3 hurricane on the Saffir-Simpson scale, capable of causing extensive damage.

The U.S. Navy sent ships to sea for safety, and disaster officials in some parts of the Southeast fretted that people may not take the threat seriously.

``Our concern is that the public may become less responsive to evacuation orders,'' said Joe Farmer, a spokesman for South Carolina's Emergency Preparedness Division. ``We recognize that as the public is exposed to more and more of these, the need for us to reinforce this message is greater.''

Hurricane Bertha, which killed nine, came ashore in North Carolina in July with sustained winds of just 75 mph, causing millions of dollars in damage.

At 8 p.m. EDT, Fran was centered about 275 miles east of Nassau, Bahamas, and 700 miles southeast of Charleston, S.C.

A hurricane warning was in effect for the northwest Bahamas, including the casino havens in Nassau and Freeport. Whitecaps in the water off San Salvador island in the Bahamas forced Club Med to declare its beach off limits. Residents throughout the country were told to stay indoors.

San Salvador administrator Charles King said winds were near tropical storm force Tuesday afternoon.

``Apart from that, things are pretty much the same,'' he said. ``We feel as though it will be a minimal hurricane, but we are watching and listening to the reports. We are ready to take the necessary precautions.''

The Navy wasn't waiting. In Jacksonville, Fla., 14 ships from Mayport Naval Station headed for the open sea.

In North Carolina, business owners already suffering the effects of Hurricane Bertha were bemoaning more tropical weather. ``It was the worst Labor Day I've ever had, and I've been in business 41 years,'' said Carol Dillon, owner of the Outer Banks Motel on North Carolina's Hatteras Island.