Underwater vision method for low-visibility turbulent conditions

A terrible disaster has recently happened in Portugal. A Bus with 60 people felled into a turbulent and very dirty river. In the bodies rescue operations that followed, a device has been Invented and tested which can visualize underwater objects whose rough location is obtained by standard acoustic sonar methods. This was the only alternative to the impossibility of human diving or the use of any Unmanned Vehicle, hardly suitable for such extreme conditions. A canvas flexible diving bubble having a transparent window was filled with clean water. An underwater camera and light within the bubble transmit video to the surface through an electric cable. The whole set is maneuvered with the help of ropes and a rudder. A weight is used to overcome impulsion forces causing the device to dive. In the case of strong currents, like in the mentioned river situation, a rudder is useful for orientation of the search procedures. Given the near-zero visibility, an iteration line is followed during searches and as soon as the diving bubble touches an object, the camera transmits the contact image profile. This Information, despite incomplete and 2-dimensional, can be good enough to identify medium-size objects like sunk cars, buses or boats. Also, holes can be remotely located and used to fix hooks for further hoisting. The device working principle can also be applied to explore objects in very polluted sea waters, as In case of severe oil leaks. Any non-transparent fluid in a tank can now be inspected for possible leaks with the use of this method, provided that the viscosity is not high enough to prevent an optical path between the clean water medium and the Immersed object when approached by the bubble.