It was a rescue that police said had never been done before: hanging off the edge of a Staten Island ferry boat.

They were there because an emotionally disturbed man had inexplicably climbed out of the window onto a railing on the outside of the ship, seemingly ready to jump.

Then, after trying to reason with the silent would-be jumper, Officer Gambino who was roped to the boat from an anchor point above, moved like lightning to grab hold of the individual and press him up against the side of the boat.

"Some people were in dry suits and some were in rope harnesses in case he went into the water or stayed on the ferry," said NYPD Emergency Service Unit Sgt. Darion Brooks. "We were prepared for both."

Brooks told ABC 7 news that this particular rescue strategy had never been attempted before, but that the ESU trains for dozens of different situations, some of which have involved potential jumpers.

The moment of arrest was captured in stunning detail by a news helicopter, and the man was transported to a hospital where he could receive psychiatric attention.

WATCH the rescue below…

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