The 68-year-old windsurfer, identified as Joe Rocco, drowned after Hurricane Irene had blown through Long Island, as strong winds and pounding surf lingered in her wake.
He entered the water off Grandview and Parkview drives in Shirley at about 4 p.m., said Suffolk Det. Sgt. Thomas Groneman.
Rocco was with a girlfriend and some other people, Groneman said.
"He thought he could handle it and went out in the water," Groneman said. "He fell over and wasn't about to stay afloat."
With Matt Chayes