Abstract: A PV unit for use on a body of water includes a module array including at least one PV module and an array holder designed to move the module array between an operating position on a surface of the body of water and a submerged position below the surface of the body of water. The array holder includes fixing means for coupling to a bottom and/or to the surface of the body of water. The module array is movable in a direction relative to the array holder.