KEY WEST, FLA., FEB. 13 -- A U.S.-registered ketch was under tow to Florida today after it was fired on by a Cuban gunboat, boarded, released and then boarded again, the Coast Guard said.

Coast Guard Lt. Cmdr. Jim Simpson said the 48-foot sailboat Tranquility encountered difficulties on its return to the United States and a Coast Guard cutter took it in tow. He did not know when the vessels would arrive in Key West.

The Tranquility, carrying a crew of three, was first stopped Thursday about 9:30 p.m., he said.

Crew members radioed a nearby merchant vessel, saying shots had been fired across the Tranquility's bow and the boat was being boarded just off Cuba's northern coast. No one was injured.

"The Cuban foreign ministry said the vessel had drifted into Cuban waters due to a lack of wind," State Department spokesman Rudi Boone said.

Simpson said another Coast Guard cutter established contact with the vessel about 8 p.m. Friday.

"They reported they had been released from the Cuban port of Nuevitas and sailed about 25 miles and then they were stopped again and boarded by Cubans, and released," he said.

The Coast Guard identified the crew as Ron Whaley and his wife, Cecelia, and Todd Delaney. Their home towns were not known.