To enable Fish Alarm, use the UP and DOWN arrow buttons to adjust the size return you want to be alerted to: large fish only, large and medium size fish, or all fish. Then press ENTER to enable the alarm. Remember that it is impossible for sonar to deter mine if a signal return is a fish or some other type of object or suspended debris. Any object not connected to the bottom is normally a fish and is portrayed as a fish symbol. The strength of the reflected sonar signal from a target is a good indicator of the size of the target, and the fish symbol displayed represents the strength of the signal reflected from it.
ID
ID is the automatic identification of target returns based on the strength of the returned signal and other factors. Three options are available: ID "On" displays targets' as one of three different size fish symbols. arrow buttons, and press ENTER. Whenever the depth of the water beneath your boat is equal to or less than the selected alarm depth, a continuous alarm will sound.