Tropical Storm Chris swept through the eastern Caribbean on Wednesday, skirting several islands but forcing cruise ships to change course and tourists to evacuate small islands as it threatened to turn into the first hurricane of the Atlantic season.

A hurricane watch was issued in the southeastern Bahamas and the Turks and Caicos Islands, meaning hurricane conditions with winds of at least 74 mph were possible by late Thursday.

Authorities in the Bahamas, an archipelago of 700 islands accustomed to stormy weather, urged people to stock up on water and canned food and to board up their windows.

"We are prepared for Chris," said Karl Smith, director of the Bahamian National Emergency Management Agency.

In Staniel Cay, about 75 miles south of Nassau, boat owners secured their vessels and tracked the storm's progress through the eastern Caribbean.

Click here to visit FOXNews.com's Natural Disaster Center.

"We're just battening down the hatches and tying everything down," said Ernie Sullivan, a boat owner at the Staniel Cay Yacht Club. "You just can't say if this thing will pick up steam."

Trevor Basden, a senior meteorologist with the Bahamian emergency agency, said he expected Chris to strengthen into a minimal Category 1 hurricane as it passed through the chain Friday.

The storm top sustained winds of 60 mph as it moved west-northwest toward Puerto Rico and the U.S. and British Virgin Islands.

Some 600 tourists evacuated Culebra and Vieques, small islands off Puerto Rico's east coast, as the storm approached. The storm was projected to pass at least 100 miles north of Puerto Rico, but could produce strong gusts of wind and up to 8 inches of rain, creating the risk of flash floods and mudslides, authorities in the U.S. territory warned.

The center of the storm was about 115 miles north-northeast of St. Thomas in the U.S. Virgin Islands in the late afternoon Wednesday.

Royal Caribbean, the cruise line operator, said it was altering the itineraries of three ships — the Navigator of the Seas, the Explorer of the Seas and the Freedom of the Seas — to avoid the storm.

There were no reports of major damage or injuries as the storm crossed over the Leeward Islands.

Richard Pasch, a hurricane specialist at the U.S. National Hurricane Center in Miami, said the storm was likely to skirt the island of Hispaniola, which is shared by the Dominican Republic and Haiti, where even minor storms can send water gushing down denuded hills.

Forecasters say the storm was likely to strengthen as it traveled on a path that could take it into the Gulf of Mexico.

In Anguilla, Chris brought heavy rain and strong winds overnight but the storm was much less severe than expected because it shifted to the north at the last minute, said Elizabeth Klute, director of the disaster management agency for the British Caribbean territory.

"It just kind of skirted us," Klute said. "It's moving on."

People in the islands of Antigua and St. Maarten awoke to a light rain. There were no reports of major flooding or other damage from the storm.

The first named storm of the 2006 season, Tropical Storm Alberto, swept over Florida in mid-June, then plowed northward along the U.S. coast past the Outer Banks. It was blamed for one death.

Last season was the worst in more than 150 years of records. A record number of tropical storms and hurricanes formed, including the devastating Hurricane Katrina.