Abstract: An arrangement for generating an artificial swell in a body of liquid contained in a container, such as a marine experimentation tank, a swimming pool, or the like, includes an elongated float parallel to a rear wall of the container and having such a cross section that a rear wall of the float is substantially vertical and generally parallel to the rear wall of the container and a front portion of the float has a nose-shaped configuration. A mechanical device is connected to the float and is operative for imparting an alternating horizontal motion to the float.