The (Easton) Express-Times says the man was reported missing just after 11:30 p.m. Saturday at the Dutch Springs scuba center and water park.
Colonial Regional police said officers and Bethlehem Township emergency crews responded and found the victim at about 3:15 a.m. Sunday.
Northampton County Coroner Zachary Lysek identified the victim as 46-year-old Izydor Poplawski, who was pronounced dead at the scene. Lysek ruled the death an accidental drowning.
On Aug. 18, a New Jersey man died while diving at the former cement quarry in Lower Nazareth Township, which attracts about 30,000 divers a year.