Yeah, it does have 'issues' between around 15 and 25knots..... usually generated by what I can only make out as something like a pocket of air. I don't think I'll ever get around it cos of the deep 'v' hull which affects it somewhat. I'd like to mount the depth transducer in the bilge well, but there isn't much room there with the bilge pump as well.
To be honest, it doesn't bother me too much, and when I'm in shallow areas, I'm not bombing around anyway. It has worked perfectly most of the time this year with the exception of the transducer popping up every so often in rougher weather due to it thinking it's on a beach
I may replace the large transducer for a smaller one (like I had on my previous 160 Blue) next year, but for now it can stay as it is.