Abstract: A device for measuring the wake of a sailing model in a trail tank is equiped with a platform capable of pursuing the model in the same direction and at the same speed as the model. The device includes five optical point measurement heads, carried on the platform and capable of moving horizontally with respect to the platform and crosswise with respect to the direction of pursuit of the model, thereby scanning the wake transversely and measuring the water surface undulation due to the model wake, in five adjacent vertical parallel planes forming a strip.

Abstract: A hydrodynamic test apparatus including a model support which comprises a submerged frame equipped with rollers and resting on the bottom of a tank is disclosed. A removable plate is attached to the top of the frame and a linear induction motor is attached to the side of the frame. The linear induction motor is supplied with current by conductor rails affixed to the bottom of the tank.