On October 7, 1995, about 1200 Alaska daylight time, a float equipped Cessna 180K, N64337, collided with a sandbar while taxiing from landing, in Christianson Lagoon on Unimak Island, about 55 miles southwest of Cold Bay, Alaska. The airplane was being operated as a visual flight rules (VFR) local area positioning flight under Title 14 CFR Part 91 when the accident occurred. The airplane, operated by Clearwater Air Inc., Soldotna, Alaska, sustained substantial damage. The certificated commercial pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed. The flight departed from Bear Lake, Port Moller, Alaska, about 1045. A Federal Aviation Administration (FAA) inspector, Anchorage Flight Standards District Office (FSDO), reported that the pilot was positioning the airplane in support of hunting clients. The pilot indicated that he circled the lagoon to assess the wind and water conditions. The pilot landed to the west and as the airplane was slowing off the step, the floats struck a submerged sand bar. The pilot reported that overcast skies and the color of the lagoon bottom prevented him from seeing the sand bar. After colliding with the sandbar, the airplane nosed over but remained floating upside down. The airplane received damage to the vertical stabilizer and rudder.