SX90 looking for cod, with audio line

Simrad Omni sonar SX90 (SX92) near Kodiak, Alaska searching the bottom for Cod with a 20 to 30kHz FM pulse for great resolution and frequency response on fish targets. The audio line is activated in this video, showing an echogram along bearing of the white line. Automatic Gain Control is used to filter out the bottom signal, showing you the fish. A narrow beam in comparison to the competition lets you find fish close to the bottom and surface, at long range.