About Echosounders and Sonars
From the very basic units used by inshore and inland water fisherman, through the more sophisticated units used by serious sports fishermen and the smaller commercial fishing boats, to the very high powered and sophisticated units that are used by deep sea fishing vessels.

Echosounders, Fishfinders and Sonars...
All the above terms are used to describe equipment that uses ultrasonic pulses to detect objects underwater. The equipment has three basic components: Display unit, transceiver and transducer. The display unit gives some sort of underwater picture, the transceiver generates the necessary signal to be transmitted and in turn processes the received signal and the transducer or "eye" is the device that changes the electronically generated signal into an ultrasonic pulse and in turn changes the received ultrasonic pulse into electrical form to be processed by the receiver.

Equipment Types:
For the most part echosounders/fishfinders/sonar's are basically the same. You can find manufacturers of fishfinder equipment below