The Texas Parks and Wildlife Department (TPWD), the primary water patrol agency in the State, reports on its successful use in its underwater work of an off-the-shelf technology used for commercial and recreational fishing.
Lt. Michael Mitchell of the TPWD took a side scan sonar imaging device, which is typically hard-mounted into one vessel, and devised a portable box, power supply, and transducer mount that can be used in any boat. In one drowning case, other agencies had used manual searching methods for many hours before the scanning device was brought to the scene. Within 30 minutes, the device had located three specific areas of interest. Divers investigated and located the victim in a flood-swollen river. Investigating officers can carry a device in their vehicle's back seat. More than 100 side scan sonar units are now being used throughout the State. Mitchell advises, however that it takes training in order to interpret the sonar images. He teaches a multi-day training course that includes classroom sessions and a field exercise that consists of finding an object in a lake. Investigators from outside Texas who are interested in the technology could start by researching side scan sonar technology on the internet before contacting Mitchell for more information.