NEW YORK - In a bizarre case of “marine mischief,” a Brooklyn artist manning a replica Revolutionary War submarine caused a scare Friday morning after police found the strange-looking vessel foundering in a security zone near the docked Queen Mary 2, authorities said.

The handmade wood and fiberglass vessel, at the end of a tow rope tied to an inflatable boat, was spotted by police near the luxury ocean liner docked at the cruise ship terminal in the Buttermilk Channel off Red Hook in Brooklyn.

“It was a strange sight,” said Coast Guard Petty Officer Angelia Rorison.

Police held the artist, Philip “Duke” Riley, and two other men, both from Rhode Island, for questioning. But there was no indication the trio meant any harm with the replica of the 1776 “Turtle submarine.”

One of the Rhode Island men claimed he was descendant of David Bushnell, the inventor of the original one-man vessel that inspired the replica, police said.

The makeshift sub “is the creative craft of three adventuresome individuals,” Police Commissioner Raymond Kelly said in a statement. “It does not pose any terrorist threat. ... We can best summarize today's incident as marine mischief.”

The brown, egg-shaped wooden vessel was a replica of a submarine used during the American Revolution, Rorison said.