To the dozen divers of the Hennepin County Sheriff's Office water patrol, delving into the murky waters of Twin Cities rivers and lakes closely resembles stumbling in the dark.
"Close your eyes and start swimming and feeling around with your hands," described Deputy David Kolar. "That's basically what it's like."
To expedite underwater searches and help protect divers, the Sheriff's Office has been working to secure funding for the team to receive an underwater remotely operated vehicle (ROV), which could search the dark depths to help locate criminal evidence and possibly drowning victims.
Sgt. Clayton Sedesky said that diving in nonclear water, such as what is found in Minnesota, can be perilous.
"There's unknown dangers all over," Sedesky said.
In the water, divers experience zero-visibility that can cause them sometimes to run into sunken logs, ensnaring vegetation or even cars, he said.
The ROV would be used after the dive team deploys sonar to scan the area for images of targets underwater. Instead of a diver being sent down to feel around for the target, the ROV could be used to go underwater to scope out potential finds with the help of a camera, lights and a manipulator arm. Then a diver could be sent with better accuracy to retrieve the target.
The ROV hopefully would cut the team's recovery time in half and eliminate the need to have all divers on standby for each search, Sedesky said.
The Sheriff's Office is in the process of identifying grant money and other funding options to pay for the ROV, said Lisa Kiava, spokeswoman for the Hennepin County Sheriff's Office.
Commander John St. Germain of the Ramsey County Sheriff's Office, whose water patrol has had an ROV for about two years, said that it has been "a very handy tool."
"When you're diving in Minnesota lakes, it's not like the Caribbean," he said. "It's dark. It's murky."
The ROV is especially helpful when divers are looking for drowning victims and when vehicles have fallen through the ice, he said.
St. Germain estimated that the ROV cost more than $100,000 including add-on features.
Hennepin County water patrol hopes to have an ROV this fall, Sedesky said.
Nicole Norfleet • 612-673-4495 Twitter: @stribnorfleet