The Offshore Oil and Gas Industry in the North Sea has many requirements for 3D measurements in air and underwater. A market audit found that the use of film based photogrammetry was being rejected for many applications because the information was not available fast enough. A development project was set up to replace the photographic cameras with a choice of video of high resolution digital electronic cameras, and the analysis system with a personal computer based image processing system. This product has been in operation with Remotely Controlled Underwater Vehicles since September 1992. The paper deals with the ongoing development of the system, including the automation of the measurement process. It introduces the application of the system as a closed-loop control system for underwater manipulators.