On August 29, 1999, about 1000 eastern daylight time, a Lake LA-4-200, N8002H, registered to a private individual, impacted with the water while taxiing on a lake near Winter Haven, Florida. Visual meteorological conditions prevailed at the time, and no flight plan was filed for the 14 CFR Part 91 local training flight. The airplane sustained substantial damage. The two airline transport-rated pilots reported no injuries. The flight had departed from a seaplane base near Winter Haven, about 0930. The flight had landed on the lake after the pilots had been practicing landings and takeoffs. The pilot-in-command/certified flight instructor (CFI) stated, "...while attempting a water take off in a left step turn the bow was allowed to get too low causing the right front portion of the hull to dig in and spin the aircraft about 180 degrees...as the flight instructor I took control of the aircraft when the student did not correct the pitch attitude, but a split second too late." The pilot receiving instruction stated, "...while completing a step turn taxi maneuver to the left apparently I allowed the bow to become too low swinging the aircraft 180 degrees to the right causing damage...."