Humminbird Wide View - Manual (Page 29)

Sensitivity
As the Wide View receives returned
signals, the sensitivity of the receiver is adjusted
automatically based on a number of factors such
as the depth of the water, and the signal clarity. In
murky water, full of debris, the Wide View will
select a lower sensitivity setting. In clear
water, where there is little debris to defract the
sonar signal, the sensitivity is set higher.
The Sensitivity menu allows you to "bias"
this automatic setting up or down based on
personal preference.
You can select a bias of +5 to -5, for 11 different bias settings. A bias setting of "0" has
no effect on the automatic function. A +3 setting selects a sensitivity setting three steps higher
than the unit would normally select, so even the smallest returns are displayed onscreen.
A setting of -2 sets the sensitivity two steps below what the unit would normally select, so
only the largest targets or other returns are displayed.