Two ships and a plane took part in the second day of the search, which was centered about 85 miles (137 kilometers) northwest of Puerto Rico, Coast Guard spokesman Ricardo Castrodad said.
The man, identified as 42-year-old Jason Gregory Rappe of Olympia, Wash., was reported missing Thursday by his wife from the Holland America cruise ship Eurodam. A baseball cap belonging to the passenger was found on one of the decks and he is believed to have gone overboard.
"At this point, we are actively searching," Castrodad told The Associated Press. "We are hoping to find a survivor."
He said the Coast Guard had not decided how long it would search. He said such decisions are made on a case by case basis depending on such factors as the weather and the physical condition of the missing person.
The Eurodam was traveling from St. Thomas in the U.S. Virgin Islands to the Bahamas when Rappe was reported missing.
The ship turned around to join the search, but Holland America spokeswoman Sally Andrews said the ship had since resumed its voyage. It was scheduled to return to Fort Lauderdale, Florida, on Saturday