The study resolves conflicting observations of previous research and adds to our knowledge of surface film locomotion by the Gerridae. Water striders perform 2 kinds of movements, gliding and leaping. The power thrust for these movements is provided by mesothoracic legs only, with the pro-and metathoracic pairs giving stability to the body. In gliding motion metathoracic legs do not move. In leaping motion they move, but frictional drag and limb inertia are more likely responsible for their relative backward movement than a rowing action. Backstroke recovery of the mesothoracic legs in both motions is by lifting and bringing them forward over the head. Turning is done by unequal power strokes of mesothoracic legs, while the metathoracic leg on the inside of the turn serves a pivotal function.