The US2 in the Terrova is 83/200kHz ...

You can choose HB 83/200kHz and utilize basic 83kHz and 200kHz ...

Or you choose the CHIRP choices centered around the 83kHz and 200kHz and utilize sweep frequency technology ...

Which is best is determined by water conditions, bottom composition, witchcraft, etc ...

Experiment to see which gives satisfactory results for the given conditions that day ...

Rickie