After 14 passengers had boarded the float-equipped Twin Otter, the flight was cleared for west bound takeoff by Male Tower. Wind was 230/09 knots. The total length of the east west runway available for takeoff and maneuvering up to the Hulhule sea wall is approximately 1000 meters. The aircraft seemed to accelerate slowly. Approaching the sea wall captain, realising the height of the aircraft, pulled on the controls to clear the obstacle. The aircraft left float struck the sea wall and separated. The left wing then rotated upwards at the pivot point at the trailing edge of wing. The airplane then impacted runway 18. The right hand float was pushed upwards, causing it to strike the no. 2 propeller. CAUSAL FACTORS: The crew failed to select the flaps to the standard 20 degrees as required. The crew failed to abort the take-off. The Pilot-in- Command did not take any action to abort the take-off as the aircraft approached the sea wall.