Man-Yi typhoon struck the Japanese Okinawa island mid-July 2007, with winds blowing at speeds between 230 and 295 km/h. It caused several casualties, as well as important material damage. Typhoons are quite frequent in the region, but they usually appear later in the year; Man-Yi is probably the strongest typhoon ever observed in July. Such meteorological monsters (called cyclones, hurricanes or typhoons depending on the region) feed upon the ocean heat to release a huge quantity of energy. They causes raging winds (winds faster than 33 m/s --118,8 km/h --are a criterion to classify a tropical storm as cyclone), very high waves, torrential rain, and all the damages that follow.