The present invention relates to methods and systems for performing underwater surveys, in particular on sub-sea installations such as oil and gas pipelines, risers, well-heads and so on. Further the invention relates to providing an augmented underwater image of a scene for use in an under-water survey, using an underwater imaging system comprising a light module, image processing module and a camera module, the light module comprising a plurality of light classes each light class having one or more light sources. The invention uses sequential imaging to provide the augmented output image.