Underwater patrol

Technology has evolved to the point where law enforcement officers can search for and retrieve a sunken vehicle, a submerged murder weapon or a floating body using a device no bigger or heavier than a portable vacuum.

The Nevada County Sheriff’s Office Tuesday showed off its new $50,000 Remote Operated Vehicle, or “rover,” a 30-pound neon-green device designed to aid in underwater patrol around dams and search for evidence and bodies in area lakes.

The super-durable, watertight vehicle is equipped with sonar that detects objects up to 300 feet in every direction. It has a video camera and an extended grabbing arm in the front.

“This device will significantly reduce the risk to divers searching for drowning victims,” Sheriff Keith Royal said. The rover also can patrol Stampede Dam at Boca Reservoir for any attempts to damage it.

“If that dam were compromised, within a matter of minutes, Reno would be under water,” Royal said.

The attached cord allows the device to dive as deep as 600 meters, far beyond the 100 feet human divers can safely go, he said.

The vehicle’s camera and its small but powerful propeller-like thrusters are operated with a joystick and other controls on a remote panel by officers on shore or aboard a vessel.

The sonar transmits through the device’s umbilical line to a remote computer screen, where floating or trapped objects show up as blips of varying sizes.

“It’s easy to operate,” Sheriff’s Sgt. Jeff Pettitt said. “Any kid who plays video games could operate it.”

The high-tech vehicle was purchased with a federal grant from the U.S. Office of Homeland Security, and its cost will quickly be offset by its efficiency, Royal said.

An intensive search in 2006 for a 17-year-old boat accident victim in the murky water of Boca Reservoir, for example, lasted several days and required several dive teams. That cost the county $55,000, he said.

“If you have a drowning victim, you can’t leave the scene,” Royal said. “If you can’t find the body, you have to keep looking, for the family’s sake. This device will help close the gap with speed of recovery and less danger to divers.”

Only a handful of law enforcement agencies across the country — mainly in coastal areas — have purchased the expensive technology, so Nevada County’s rover will most likely be loaned out to other area agencies as necessity dictates, he said.

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To contact Staff Writer Robyn Moormeister, e-mail rmoormeister@theunion.com or call 477-4236.