Housed in palm-sized titanium enclosure, Subsonus USBL combines 8-channel calibrated hydrophone array with integrated inertial navigation system to provide position, velocity, and heading at depths of up to 1,000 m. Self-calibrating system requires no extra equipment or user intervention for setup, minimizing risk of operator errors. Operating on inverted or standard USBL scheme, Subsonus performs all processing and uses single Ethernet connection for data output.