Acoustic Signal Interference
Acoustic interference reduces the performance of your transducer. While you cannot control noise from agitated water, waves, fish, rain, and other vessels, you can minimize acoustic interference by installing your transducer away from propellers, shafts, cables, and other machinery.
You should also avoid mounting the transducer aft of thru-hull fittings, water intake or discharge ports, or hull irregularities.
NOTE:
If you use multiple transducers, you should mount them at least 60 cm (24 in.) apart. Running two transducers of the same frequency simultaneously causes the transducers to interfere with each other. You may run two transducers of different frequencies simultaneously.