Stay away from chines, they cause turbulence and turbulence causes bubbles and bubbles cause 'clutter' and loss of bottom signal.
Tip: Use a mounting board, like this nylon board. This prevents unnecessary drilling of holes and “oops’s”.
Height of transducer is critical, too high and you lose contact with water. Too low and you create unnecessary turbulence and spray, not to mention running the risk of having this expensive piece of equipment knocked off the transom at high speed.
Transducer angle plays a really big part in the quality of your echo (display), 90% of customers who have complained of “poor quality”, have had their angle wrong. A transducer that is ‘Toe Heavy’ (image on the right), creates turbulence and thus a poor echo. A transducer that is fractionally ‘Heel Heavy’ (image on the left), will give the best result in all conditions. The only down side is that your fish arches won’t be 100% symmetrical, see bottom images.