Autonomous Underwater Vehicle Sentry

AUV Sentry is lowered into the water to start a dive during a 2016 expedition to explore deep-water canyons off the coast of North Carolina. Image courtesy of Exploring Carolina Canyons expedition.

AUV Sentry is lowered into the water to start a dive during a 2016 expedition to explore deep-water canyons off the coast of North Carolina. Image courtesy of Exploring Carolina Canyons expedition. Download larger version (jpg, 4.1 MB).

Sentry is an autonomous underwater vehicle (AUV) capable of diving to depths of 3.7 miles (6,000 meters) without direct human control or connection to a ship and can remain submerged for up to 40 hours.

Operated by the Woods Hole Oceanographic Institution ’s National Deep Submergence Facility , Sentry’s unique design allows it to “fly” very close to the seafloor on rough terrain. Common missions for the vehicle involve surveying the seafloor to map features such as hydrothermal vents or deep-sea coral reefs or even shipwrecks and oil wells. Sentry can also make high-resolution maps of a region so that scientists can better understand large-scale geological processes.

Sentry carries an extensive (and growing) suite of scientific instruments . The vehicle has a sonar mapping system that includes a high-resolution multibeam echo sounder capable of generating detailed three-dimensional models of the seafloor with a resolution as fine as 20 inches per pixel. Sentry also has a high-resolution digital camera that can take a picture every three seconds, providing scientists with an immense amount of data about the seafloor. In addition to its standard sensors, Sentry has carried several custom-designed instruments, including pumped filter samplers to collect plankton and a miniature mass spectrometer.

Sentry can be used as a stand-alone vehicle on a wide range of research vessels but can also be used very effectively in tandem with human-occupied vehicle Alvin or other remotely operated vehicles.

 

Submersible Namesake

Sentry is much like a guard, keeping watch.

Sentry engineers (bottom, Ian Vaughn and Andy Billings) and the ship’s deck crew (GVA Fountain and CB Walker) work to secure tag lines on the vehicle. Once secured, these lines help them to steadily guide the Sentry onto the deck and into its cradle. Image courtesy of DEEP SEARCH 2017, NOAA-OER/BOEM/USGS.

Sentry engineers (bottom, Ian Vaughn and Andy Billings) and the ship’s deck crew (GVA Fountain and CB Walker) work to secure tag lines on the vehicle. Once secured, these lines help them to steadily guide the Sentry onto the deck and into its cradle. Image courtesy of DEEP SEARCH 2017, NOAA-OER/BOEM/USGS. Download larger version (jpg, 6.0 MB).

Sentry carrying the SyPRID sampler (aka, Plankzooka) in 2015. This unique system filters almost two million liters of seawater per hour to collect larvae from the deep ocean, allowing scientists to precisely study how deep-sea organisms reproduce and spread through the ocean. Image courtesy of Carl Kaiser – Woods Hole Oceanographic Institution.

Sentry carrying the SyPRID sampler (aka, Plankzooka) in 2015. This unique system filters almost two million liters of seawater per hour to collect larvae from the deep ocean, allowing scientists to precisely study how deep-sea organisms reproduce and spread through the ocean. Image courtesy of Carl Kaiser, Woods Hole Oceanographic Institution. Download larger version (jpg, 99 KB).

About the Submersible

TYPE
Autonomous underwater vehicle
LENGTH
9.7 feet (2.9 meters)
WIDTH (FINS EXTENDED)
7.2 feet (2.2 meters)
WIDTH (NO FINS)
2.7 feet (0.8 meters)
HEIGHT
5.8 feet (1.8 meters)
WEIGHT
2,750 pounds (1,250 kilograms)
MAXIMUM OPERATING DEPTH
3.7 miles (6,000 meters)
ASCENT/DESCENT RATE
131 feet (40 meters)/minute
OPERATING SPEED
2.3 knot (maximum speed)
OPERATING SINCE
2010