On June 17, 1999, about 1012 Eastern Daylight Time, a Bell 206B-III, N94WF, was substantially damaged during a collision with water at Tinicum, Pennsylvania. The certificated commercial pilot sustained minor injuries. Visual meteorological conditions prevailed for the local flight that originated from Erwinna, Pennsylvania. No flight plan was filed for the aerial application flight conducted under 14 CFR Part 137. According to the pilot, he departed from "Landing Zone 5," an open field adjacent to the Delaware River. He intended to perform aerial application for 20 minutes, and return to the landing zone. He stated that while spraying for blackfly over the Delaware River, his attention was momentarily diverted, as he was looking at a flow gauge inside the cockpit. The pilot further stated that he flew too low, causing the skids to contact the water. The main rotor blades subsequently struck the water, and the helicopter came to rest on its side, in approximately 3 feet of water, about 2 to 3 miles from the landing zone. Examination of the wreckage by a Federal Aviation Administration Inspector did not reveal any pre-impact mechanical malfunctions, nor did the pilot report any.