A passerby noticed the body in the Conservancy Water on the east side of the park near 74th St. around 8 a.m., police said. The witness jumped in the water in an attempt to save the man before calling 911, the NYPD said.
Police and Emergency Medical Service workers responded and pronounced the man dead at the scene.
Officials have not determined a cause of death, and have not made any arrests. It is best known as a place for springtime boating and is mentioned in E.B. White's "Stuart Little".