An impressive number of laser-based sensors for 3D vision for terrestrial applications have been developed so far, making it a mature and expanding market worth billions of euros. When it comes to the subsea environment the presence of water, combined with the demand to operate at depth, acts as game-changing factors and considerable scientific and technological challenges arise. This chapter concentrates on selected techniques for subsea 3D vision and ranging using laser-based sensors, with priority given to projects where the efforts have been focused on developing devices ready to be deployed in real scenarios. © 2013 Woodhead Publishing Limited. All rights reserved.