My transducer doesn’t throw a noticeable roostertail and performs well (looking down) up to about 30 mph….then it gets caught up in wake turbulence and stops providing depth readings until I slow back down again.
One downside of my ‘ducer mounting position is that it is exposed to stuff in the water column. My primary concern at this point is ice this winter on P4. We’ll see how it goes.
A through-hull (for high-speed down-looking readings) coupled with the SI for slower side images is becoming the standard mounting scheme. The 2 ducers are connected via the standard Y cable provided with the unit, and the most recent software versions automatically switch to the through hull ducer for high speed readings.
I’ll be adding a through hull ducer as soon as I can.