On March 12, 2003, at 1000 eastern standard time, a Piper PA-18 floatplane, N276T, was substantially damaged while taxiing on Lake Anna, near Mineral, Virginia. The certificated commercial pilot and certified flight instructor were not injured. Visual meteorological conditions prevailed and no flight plan was filed for the instructional flight conducted under 14 CFR Part 91. According to the pilot, who was receiving floatplane instruction, the flight had originated from Warrenton, Virginia, and proceeded to Lake Anna, to conduct on-water maneuvers. After landing on the lake several times, the flight instructor requested that the pilot perform a few step taxis. During one of the taxis, as the floatplane was being turned to the right, the pilot stated, "I don't think we are going to make it." The instructor replied, "Put in more rudder." The pilot informed the instructor that he already had applied full right rudder, and added full power in an attempt to "pull us through the turn." As the floatplane neared the shoreline, the instructor decreased the power, and the left wing struck a tree. The airplane turned abruptly to the left, and came to rest along the shoreline. A Federal Aviation Administration inspector examined the wreckage after the accident. He observed substantial damage to the left wing. The flight instructor, who also owned the floatplane, failed to return the pilot operator report, NTSB Form 6120.1/2, sent to him on three different occasions.