FuzzyGrub said:
If this is a large transducer, like many Humminbirds, they typically take more trial and error to get them to read while getting on plane and on plane.
Not to hijack the post, but that's what I'm into right now. My Humminbird Si transducer works great at fishing speed, but I don't get much on plane. I've tweaked the height / tilt several times, and it looks like the only solution to getting readings at speed is to add a second, 2d, transducer and a Y cable at the head unit. So, while I'm mounting a board for the new 2d transducer I might just add one for the Si. Adding the 2d transducer also has the benefit of (probably) being able to raise my Si transducer up a little, and avoid the possibility of it hitting anything in the water.
Rooster tails can be a problem (it is on mine), but I saw this solution on another site. Haven't done this myself, so can't say if it works or not. BTW, the transducer board in this pic looks a little low, probably should be mounted 1/4" higher to avoid becoming a trim tab.