On July 17, 2013, about 1730 eastern daylight time, an experimental, amateur-built Kolb MK III amphibian airplane, N175TS, operated by a private individual, was substantially damaged while landing on Sylvia Lake, Fowler, New York. The airline transport pilot was seriously injured. The personal flight was conducted under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and no flight plan was filed for the local flight that originated from Sylvia Lake about 1720.The pilot was seriously injured in the accident and could not recall the time period from about 2 hours prior to the accident, until 10 days after the accident. The pilot added that although he could not recall the accident, he remembered that his intention was to complete a local flight after not flying for about 2 weeks. The pilot intended to takeoff, circle the lake at 1,000 feet above ground level, then return and land on the lake. The pilot also reported a total flight experience of 12,000 hours; of which, 100 hours were in the same make and model as the accident airplane. The pilot had flown about 5 hours and 2 hours, all in the accident airplane, during the 90-day and 30-day periods preceding the accident, respectively. A witness, who was riding a personal watercraft on the lake, reported that the airplane was performing takeoffs and landings. During short final approach, as the airplane was nearing the southern shore, the nose lowered and the airplane impacted the water. The witness and another boat operator assisted the pilot out of the airplane. Examination of the wreckage by a Federal Aviation Administration inspector revealed substantial damage to both wings and the fuselage. The inspector was able to confirm flight control continuity and did not observe any preimpact mechanical malfunctions. The two-seat, high wing, experimental amateur-built airplane, serial number 8906, was assembled in 1998 and equipped with a Rotax 80-horsepower engine. The airplane's most recent annual condition inspection was completed in May, 2013. At that time, the airplane had accumulated 235 total hours of operation and the engine had accumulated 35 hours of operation since new. The airplane had flown an additional 5 hours, from the time of the most recent inspection, until the accident. The recorded weather at an airport located about 15 miles southwest of the accident site, at 1758, included wind from 250 degrees at 7 knots, sky clear, and visibility 9 miles.