Doc will help you understand how sonar works and how to interpret the sonar display using underwater video correlated with sonar to help you understand what your sonar is actually “seeing”. You will be able to identify fish, baitfish, trees, hard and soft bottom like a pro.
The sonar recordings are from Lowrance color traditional sonar but all sonar displays are based on the same principals.
This 2 disc set covers basic and advanced sonar interpretation.