I have the 999 with seperate HDSI & 2D sonar transducers. I know my SI won't work at planing speed but I get solid bottom readings and contours on my 2D. I'd like to use that speed to more quickly find schools of bait fish. To date I haven't seen any on my 2D screen but not sure if that is because I just haven't looked closely enough or if they just won't register at higher speed.
How should I adjust/set my 2D sonar for high speed detection and what is the fastest speed I can reasonably expect to see these schools?