Light undergoes a wavelength-dependent attenuation and loses energy along its propagation path in water. In particular, the absorption of red wavelengths is greater than that of green and blue wavelengths in open ocean waters. This reduces the red intensity of the scene radiance reaching the camera and results in non-uniform light, known as background light, due to the scene depth. Restoration methods that compensate for this colour loss often assume constant background light and distort the colour of the water region(s). To address this problem, we propose a restoration method that compensates for the colour loss due to the scene-to-camera distance of non-water regions without altering the colour of pixels representing water. This restoration is achieved by ensuring background light candidates are selected from pixels representing water and then estimating the non-uniform background light without prior knowledge of the scene depth. Experimental results shows that the proposed approach outperforms existing methods in preserving the colour of water regions.