Towed Underwater Video (TUV)

Highlights:
  • No diving require for identifying and recording benthic communities. Much faster and safer than diving.
  • Data (videos/photos) can be georeferenced and stored for future analysis and comparing.
  • Ideal to use in shallow water down to 20 m ( 65 ft).
  • The entire setup fits easily in a day pack.
Towed Underwater Video Description:
A camera in a rig is lowered to a certain depth to record a video. For this you need:

  • Camera and Housing: In the market there are many types of digital cameras (with video recording capacities) and underwater housing. You can also use video cameras with housing. Before lowering the camera rig, you must turn on the video recording. After raising you stop the recording. This mean that some video editing must be done after the field work. Now I use a GoPro. On my first experiences using TUV I used a Canon a640 digital camera with a WPDC8 Waterproof Case.
  • Camera Rig: Is an aluminum structure. The design is simple, a double U. One for support the lead weight, the stabilization fins and the connection to the line. The other (movable) to support the housing and change the angle of the view of the camera (0º to 90º).
    Line: a 20m (65 ft) long x 3mm nylon line is used to lower and raise the camera rig. The line has marks every meter to know at what depth is the rig.
  • Depth Gauge: I use a HawkEye handheld digital SideScan sonar that give instant depth readings, from 2.5′ to 199′ feet, in 1/10th precision, before lowering the camera rig.
  • GPS: On board the vessel you need a handheld GPS to record the position on surface of the camera rig. You also need to synchronize your camera clock with the GPS. In my setup I use a Garmin Vista HCx with the track taken every second (recorded in a miniSD memory card).
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Video Examples: