Noise

Electronic Instruments: Noise is the unintentional, external signals / sound waves that interfere with the optimal operation of an electronic device. For example, noise on a Fishfinder or >Radar screen will appear as unintentional dots on the display, and results from a variety of sources. Noise can be adjusted by changing your >Sensitivity settings, but this also effects your detection of a true signal. Higher signal - noise ratios, will provide better clarity from an electronic device.

Electrical noise on a Fishfinder display, from Trolling motors, Bilge pumps, VHF radios, etc typically appears as a consistent dot pattern and can often be isolated by selectively turning off other electrical devices to determine the source. Rerouting the power cable, or connecting to an alternative power second battery can help overcome >Electrical Noise.

Hydrodynamic noise on a Fishfinder display, from Propeller and/or Hull Cavitation, has a more random appearance and is generally proportional to Boat speed. Hydrodynamic noise often results from improper Transducer installation.