On August 11, 2006, about 1030 eastern daylight time, a Richard S. Tharp Challenger II aircraft, N128RT, registered to, and operated by a private individual, as a Title 14 CFR Part 91 personal flight, incurred damage during landing at Lake Apopka, Apopka, Florida. Visual meteorological conditions prevailed, and no flight plan was filed. The private-rated pilot was not injured, and the aircraft incurred substantial damage. The flight originated from Orlando North Airport, Zellwood, Florida, the same day, about 0930. The pilot stated he departed Orlando North Airport and preceded south. According to the pilot, he intended to make a full stop water landing at Lake Apopka, approximately 3 miles south of the departure airport. He stated that during his water landing the left pontoon struck a tree stump which was submerged in the lake, and the pontoon was punctured, which caused the right wing support to fail. The pilot said that prior to the accident there were no mechanical failures or malfunctions to the aircraft or any of its systems.