Context
Which colour scale to use is mainly a personal preference based on ambient light conditions, the nature of the echoes and
your own experience. Keep in mind that in the basic scale with 12 colours, each discrete colour represents a 3 dB range of echo signal strength. This implies that the next colour is selected every time the echo strength is doubled. If you choose to use many colours, the resolution of the ST90 presentation is greatly improved. It is then easier to distinguish the difference between the various echoes of different size and/or target strength.
The Smooth Echosounder scale is based on the standard 12-colour scale. Additional colours have been added between them to make smoother colour transitions.