A Maldivian Air Taxi seaplane departed at 12:11 hrs from the MAT dock at Male International Airport, water aerodrome. It was flying fourteen tourists to the Adaaran Club Bathala (North Ari Atoll). The weather was windy and sea was rough. The estimated flight time to destination was 20 minutes. Around 12:30 the aircraft approached for landing near the floating platform located in the lagoon north of Adaaran Club Bathala. The wind was on a westerly direction 20 to 25 knots and the aircraft approached for a westbound landing. The aircraft made an orbit over the lagoon to inspect water and approached towards the platform for landing. The aircraft touched down and was cutting the top of the wave, as they usually do to find an appropriate location for stopping. Before it could find an appropriate place to stop it hit a big swell. This caused the aircraft to sway to the left and get airborne. The PIC called for a go around and tried to correct the left sway. As it was climbing with a right bank it collided with a speed boat, moored to the buoy which was located to the west of the platform. The RH float collided with the bow of the speed boat, which caused the RH float and the RH engine to detach the aircraft. The aircraft yawed to the right and the PIC managed to land the aircraft and bring it to a halt on LH float. Due to high wave current the aircraft drifted towards the shallow area and sank. The passengers and crew was able to escape the aircraft without any fatalities. CAUSAL FACTORS: – The crew’s decision to land on rough waters without giving due considerations for a rejected landing and obstacles nearby was a causal factor. – The Speed Boat moored to a buoy, close to the landing area was also a causal factor.