Boat Boy is back at it — and they can’t even ship him home.

The homeless migrant who was busted joyriding on a historic FDNY fireboat and then swiping a sailboat for another leisurely ride was released without bail Friday — only to immediately try to climb aboard an even bigger ship in Manhattan, according to sources, who said immigration officials’ hands are tied.

Juan Hernandez, 22, of Ecuador was set free by Judge Marva Brown on Friday morning after allegedly taking the former FDNY-owned vessel John J. Harvey on a wild journey down the Hudson River early Thursday before swiping a sailboat in Chelsea for another jaunt.

By noon Friday, the alleged boat bandit was back on the street and trying to get onboard the Frying Pan — a 133-foot lightship that boasts a popular floating restaurant at Pier 66, according to workers and owners.