Science & Tech

AUV Sentry

AUV Sentry
Ocean Exploration Trust

The autonomous underwater vehicle (AUV) Sentry was designed to conduct seafloor surveys at low altitudes and in rough or complex topography. The vehicle is owned by Woods Hole Oceanographic Institution, operated by the National Deep Submergence Facility, and funded by the National Science Foundation. AUV Sentry is rated to 6,000 meters (19,685 feet) and equipped with a high-resolution photo camera, an EM2040 multibeam sonar, sub-bottom profiler, and a series of other sensors to study the deep seabed. Sentry can be used as a stand-alone vehicle or with the human-occupied submersible Alvin or a remotely operated vehicle to scout regions ahead of dives by those vehicles to increase the efficiency of deep-submergence investigations.

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Sentry at-a-Glance

Depth Capacity: 6,000 meters (19,685 feet) 

Speed: 0-2.3 knots 


  • Kongsberg EM2040 (200 Khz and 400 Khz)
  • Edgetech 120/230/540 kHz side scan
  • Edgetech chirp sub-bottom profiler
  • Three APS 3-axis fluxgate magnetometers

Navigation & Communication:

  • Ultra-short baseline
  • Doppler velocity log 
  • Inertial navigation (internal)

Sensors & Imaging Systems:

  • Methane sensor
  • Seafloor photography: Prosilica GE4000C Digital Still Camera (color still camera with strobe, rated to 6,000 meters)
  • CTD sensor: Seabird 49 
  • Oxygen sensor: Aanderaa Optode
  • NOAA ORP (oxidation-reduction potential) sensor
  • Optical backscatter (OBS): Seapoint Turbidity Meter
  • Akamura redox potential probe
  • ACFR 3-D imaging system
  • Pressure: Paroscientific 8B7000-I Digiquartz depth sensor
  • Doppler velocity logger: RDI, 300kHz
  • Doppler velocity logger: Nortek, DVL500, 6,000 meters
  • Attitude sensors (pitch, roll, heading-internal):  IXBLUE PHINS III

Sampling Equipment

  • Water sampler (eDNA)
  • Sentry Precision Robotic Impeller Driven (SyPRID) plankton sampler