Dronar—Geoforensic Search Sonar from a Drone

Lightweight sonar devices may be tethered to an unmanned aerial vehicle or drone and quickly deployed over water for real-time imaging in 2D the on site creation of geolocated, interactive bathymetric maps without need a boat. We show how such data is useful preliminary stages searches, by providing geophysicists, hydrologists divers with spatial depth information, distribution dive equipment hazards as entanglement objects (weed, discarded items) sediment types. One bathymetry case study location described detail, further two summarized demonstrate reconnaissance surveys. Limitations drone-based surveys are outlined, including dense weed cover; limits flight times adverse weather conditions.