Sonar Alarms

Sonar alarms can be set to detect depth, and fish presence. A sonar depth alarm is the most basic of features in a depthfinder / fishfinder. If the boat is drifting a minimum threshold can be set which will alarm the boater of shallow water. Sometimes shallow water is more ideal for certain species of fish or habitat and a depth alarm can be set to alert the boater when a certain depth is exceeded. Most alarms are audible.

Fish finder manufacturers usually build in a software routine to the signal processing which will try to interpret returning echoes and identify fish. A fish alarm, triggered by the fish id feature, can be turned on to audibly signal the angler about the possible presence of fish.