small, free, surface-water wave with such a short wavelength that its restoring force is the water's surface tension, which causes the wave to have a rounded crest and a V-shaped trough. The maximum wavelength of a capillary wave is 1.73 centimetres (0.68 inch); longer waves are controlled by gravity and are appropriately termed gravity waves. Unlike the velocity of gravity waves, the velocity of capillary waves increases with decreasing wavelength, the minimum velocity being 23.1 centimetres per second (9.09 inches per second), where the wavelength is the maximum 1.73 cm.