Abstract: A sonar apparatus using a phased array technique for steering an acoustical beam for scanning an underwater area. The sonar apparatus includes a scanning transducer having multiple elements for transmitting and steering the acoustical beam and receiving its reflection from an object, an electronic control circuit for generating steering information and computing a relative location of the object, and an input/output section for displaying the relative location to a user. The control circuit includes a software level/align control for compensating for mis-leveling or mis-alignment during installation, a scan control capable of selecting a scan center direction and a scan width in one degree increments, a forward gain control for optimizing the sensitivity of the sonar apparatus in a forward looking scan, and a combination of a time variable gain control and an autorange control for minimizing the reflection of sidelobes of the acoustical beam.