A cooling apparatus (1) for cooling a fluid by means of surface water comprises a plurality of tubes (10) for containing and transporting the fluid to be cooled in their interior, the tubes (10) being intended to be at least partially exposed to the surface water during operation of the cooling apparatus (1). Furthermore, the cooling apparatus (1) comprises a plurality of light sources (21, 22) for producing light that hinders fouling of the exterior of the tubes (10), the light sources (21, 22) being dimensioned and positioned with respect to the tubes (10) so as to cast anti-fouling light over the exterior of the tubes (10), wherein the light sources (21, 22) have a generally elongated shape, and wherein the light sources (21, 22) are arranged in at least two mutually different orientations in the cooling apparatus (1).