Abstract: A device for protecting off-shore structures stretched between two floating towers of the "Froude pole" type against the effects of ocean swell, comprising at least four floating poles, two vertical arrays of horizontal cables, and a deflection panel assembly attached to one of the vertical arrays of horizontal cables. The floating poles comprise a rigid metal structure between two metal cylinders of the same diameter. The vertical arrays of horizontal cables form opposed catenary curves and are braced by further horizontal cables extending between them.