Police said operator Ronald Pekrul, 33, of Shirley, was traveling east in a 29-foot Kryptonite Performance speedboat on the Great South Bay –- about a mile south of Bellport Marina –- when the boat veered violently.
Pekrul and his passenger, Bruce Grimminger, 41, of Center Moriches, were ejected into the water. Both men were pulled from the water by a Good Samaritan in a nearby vessel, police said.
Pekrul and Grimminger were taken to Brookhaven Memorial Hospital Medical Center by Bellport Fire Department rescue personnel. Grimminger, who suffered head and chest injuries, died upon arrival at a hospital, police said. Pekrul was examined and released.
Suffolk County Police Marine Bureau and the United States Coast Guard responded to assist in the rescue and the vessel was impounded for a safety inspection.
The investigation is ongoing. Detectives ask that anyone who may have seen the boat prior to the incident call the Fifth Squad at 631-854-8544. The boat has a white hull with the word IN$ANITY painted on the side.