The pilot was returning to collect passengers he had conveyed to the alighting area some hours previously. This area is bordered by steeply rising ground. Because of wind conditions, the pilot was approaching from a different direction to that normally used. About 1.5 kilometres from the alighting area, the aircraft collided with power lines which were about 29 metres above the water level. The collision severed the top portion of the fin and rudder, however the pilot was able to maintain limited control. The aircraft touched down heavily on the left float, after the pilot had taken action to avoid a dinghy in his path. Although the pilot had operated into the alighting area on a number of occasions, he had been unaware of the presence of the power lines struck by the aircraft.