NOVELTY - The device has a submerged horizontally-aligned structure provided with a central opening (125) formed in a horizontally extending surface for inducing water-particle motion in a flow into and from the central opening. A turbine e.g. water turbine, is mounted in the central opening, and is driven by flow of water through the central opening. The structure is submerged within a distance of one-half wavelength of waves in a region. The structure is provided with outer guide vanes around the central opening for directing fluid flow towards the central opening.    USE - Wave energy conversion device for converting renewable energy source of water waves into usable energy to generate electric power.    ADVANTAGE - The device directly applies wave-induced water-particle motion to the turbine without any compressible air column or mechanical motion conversion components as a medium or intermediary, and focuses wave-induced flow through the center opening of the structure to reduce cost, by allowing the turbine to be smaller in size. The mechanical design of the device is simplified, can withstand robust design, and has less corrosion when the device is made of steel. The device requires less maintenance as the device is not situated at or above an air/water boundary, and is operated over a wide range of wavelengths and wave heights. The device can be operated in a multidirectional wave field, and is submerged below the water surface, so as not to be detracted from an ocean view. The water turbine is not noisy compared to an air turbine. The device is easily maintained due to the utilization of well-established hydro-technology. The device operates efficiently to convert water-particle movement directly into water turbine generated electric energy, and can control height of the sides or submergence depth of the structure. The device has reduced wave height in the down wave direction to create a calmer region for reducing coastal erosion, to provide a quieter zone and to provide a protected area for ships.    DESCRIPTION OF DRAWING(S) - The drawing shows a perspective view of a floating deep-water version of a wave energy conversion device with fixed sides.    Waves (121)    Side walls (122)    Tie-lines (123)    Venturi-shaped surface (124)    Central opening (125)