Deeper water is definitely challenging because the water column takes up so much of the screen space ...
In a deeper water situation it helps to determine what specific task one might be targeting at that specific time ...
*If looking for suspended fish close to the boat set Imaging frequency to 800kHz, SI Range to 10-15ft more than water depth (water depth 30ft = SI Range 45ft)... and adjust SI Sensitivity up to contrast the white dot echoes against the dark water column background (Contrast on Lowrance)(Gain on Garmin) ... And slow the boat down (or increase Chart speed) to elongate fish echoes where they will be easier to see ...
*If looking for fish relatively close to the boat set Imaging frequency to 800kHz, SI Range to 20-30ft more than water depth (water depth 30ft = SI Range 55ft) and adjust Sensitivity up/down to contrast white dot echoes against the darker bottom background (Contrast on Lowrance)(Gain on Garmin) ...and slow the boat down (or increase Chart speed) to elongate fish echoes where they will be easier to see ...
If looking for new structure set Imaging frequency to 455kHz, SI Range to 40-60ft more than water depth (water depth 30ft = SI Range 80ft) and adjust Sensitivity up/down to look for structure shadows (Contrast on Lowrance)(Gain on Garmin) ... And match boat speed to Chart speed (2-4mph on Lowrance because they don't have Chart speed adjustment) ...
Rickie