This book addressed classification, image enhancement and colour correction techniques for underwater images. It also discussed latest and classic state-of-artmethods for classification, contrast enhancement and colour correction of underwater images. The underwater image dataset used included images captured in natural and artifical light sources. The results of different image enhancement and colour correction methods are compared. Different quality parameters of underwater images like Robustness value, Enhancement by Entropy, Average Information Entropy, mean colour dispersion and deviation, PSNR, MSSIM are defined and used for comparison of results of various methods.