Abstract: Process designed to produce attenuation of the effects of swell in view of protecting coastal or off-shore structures or installations, characterized in that it consists in creating, from the incident swell, an undulatory type phenomenon which is materialized in the form of a "oscillating wall of water" generating a system of radiation waves whose combination with the diffracted wave present downstream from said "oscillating wall of water", produces a non-existent or low amplitude resultant.

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.