The body of a man in his 30s was discovered floating in the water off the Rockaways early Monday, cops said.

A passerby discovered the body just before 5 a.m. near Beach 91st Street bobbing near the rocks, close to a jetty, and notified police, authorities said.

EMS pronounced the man dead on scene.

Police had not released his name by Monday afternoon.

An investigation is underway to determine how he died and ended up in the water.