Abstract: A manual scan sonar integrates multiple technologies into a compact and low cost single beam sonar having the ability to generate wide sector views comparable to that of much larger and more expensive multiple-beam sonar units. The manual scan sonar uses a piezoelectric transducer, orientation and motion sensors, a power preamplifier and amplifier, and a microcomputer with a display, all contained within a compact waterproof housing. In operation, the user scans the sonar across an area, and the orientation and motion sensors monitor the user's natural human motion to provide bearing information which is processed and stored by the microcomputer. The ultrasonic information provided by the sound echoes is displayed on the display screen of the computer as a continuous sector. This sonar may be adapted for either diver-held or topside use.