Fishermen use sonars to locate large fish or whole schools of fish. The navy uses them to pinpoint enemy submarines. But sometimes sonar is also used in non-standard situations: with the help of it, law enforcement agencies were able to solve a 40-year-old case.
At Lake Foss, 110 miles from Oklahoma City, soldiers were trained using Humminbird sonar. This version of sonar is more sophisticated than the one used by fishermen. She is able to distinguish objects located more than one hundred meters under the water on either side of the vessel.
The soldiers weren't looking for anything special. Local rangers asked them to investigate the bottom of the lake as part of the construction of an additional dock. But after turning on the sonar, two old cars became visible on the display. The image was clear enough that one of the soldiers could see that the driver's side door was open.
After that, the local sheriff sent scuba divers to the bottom of the lake, and they found human remains in the cars. It turned out that the bodies belong to people who disappeared more than 40 years ago. In one car were three teenagers who went to a football match in November 1970 and never returned. The second car contained the bodies of three adults who disappeared in 1969.
Sonar technology has gotten a lot cheaper over the past few years, and Humminbird is one of many making it. The main consumers of its products are fishermen. And the current case, most likely, will allow the company to find another sales market.