In Estonia, bodies of water start to freeze in late autumn, in November. During cold winters, the ice will cover the bodies of water until early spring, up to March. This is the time when people go out onto the ice to skate, fish, or if the ice is thick enough, drive across bodies of water. Unfortunately, this is also a period when water accidents are frequent. Statistically, most ice accidents happen during autumn and in springtime, when ice cover is thin. Many such accidents could be avoided if people had basic knowledge about the nature and formation of ice.