Abstract: A device provides improved kick stroke simulation for the design and development of diving fins. The device includes a mechanical leg which provides the simulated kicking action and a controller for controlling the kicking action. The device is capable of controllable and reliable repetition of kicking strokes as would be used in swimming, thus allowing increased integrity of measured data related to the design of the diving fin itself. Use of the device allows for optimum design of diving fins depending on the environment in which the diving fin is to be employed. Design parameters improved include, inter alia, thrust of the diving fin and the effect on ankle fatigue of the user.