The right wing tip float contacted the water during a shallow turn for final approach. The aircraft struck the water violently and sank in 36 m of water in about 10 minutes. CAUSES OF THE ACCIDENT (translated from original French report): Weather conditions: Uniformly gray sky (altostratus clouds across the region and some fractocumulus at 400 meters); The absence of wind; The absence of lines on a gray and smooth lagoon. created favorable conditions for an illusion and made it difficult to assess the exact height above the water level during the most difficult operation of the flight, the water landing. The evidence indicates that no maneuver was initiated to change the nose down attitude. The pilot did not see the water. Although there was no wind, the windsock had previously stopped in a position that prompted the pilot to land facing the NW which is used once in twenty at Raiatea. In addition, the sun , even through the altrostratus could be annoying; facing the NW, the pilot had the sun three quarter from the rear. Note that during the landing opposite the NW, the lap is necessarily right to avoid overflying the city and land. Vertical visibility of the first pilot during a right turn is poorer. Finally, the slight correction of alignment by the pilot resulted the right wing striking the water at too low altitude.