When conducting missions in turbid and dirty waters, ROV cameras are no longer sufficient. Acoustic solutions provide images even in zero visibility conditions. Scanning sonars allow scanning a static area, while 2D multibeam sonars, also called “acoustic cameras”, offer a real-time dynamic image of the environment. The 3D sonars make possible the digital reconstruction of underwater infrastructures. Finally, profiling sonars offer the possibility to control the ovality and to estimate the level of sedimentation in the pipes.