AUV Sentry

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 can be equipped with many different tool packages, including a high-resolution downward-facing photo camera, a sidescan sonar, an EM2040 multibeam sonar, a sub-bottom profiler, or other sensors to study the deep seabed. 

Sentry can be used as a stand-alone vehicle, with the human-occupied submersible Alvin or paired with remotely operated vehicles as a high-speed mapping tool to improve the efficiency of deep submergence investigations. Sentry produces bathymetric, sidescan, chemical and magnetic maps of the seafloor and is capable of taking high-quality digital color photographs in a variety of deep-sea terrains including along mid-ocean ridges and at ocean margins and in complex settings such as hydrothermal vent and cold seep ecosystems. 

Sentry’s navigation system uses a Doppler velocity log and inertial navigation system, aided by acoustic navigation systems (USBL). The USBL system also provides acoustic communications, which can be used to obtain the vehicle state and sensor status as well as to retask the vehicle. In addition to its standard sensors, Sentry has carried numerous custom sensors including the PMEL-MAPR chemical potential probe, the TETHYS in-situ mass spectrometer, a 3-D camera, a gravimeter, and several other science-provided payloads. In 2015, the vehicle pioneered precision deep vent larval sampling. Recently, Sentry has also begun taking pumped filter samples.