A party-boat passenger was in grave condition Saturday after he fell overboard near Governors Island, according to police.

The victim, 30, fell at about 1:30 p.m. over the railing of the Jewel, a yacht that holds up to 330 people.

Crew members pulled him from the water and ferried him back to Battery Park, where EMS took over. He was given CPR and rushed to Lower Manhattan Hospital in cardiac arrest.