Humminbird 787c2 GPS Receiver "metric imperial" Questions

...METRIC unit instead of IMPERIAL? I bought this Humminbird 787c2 from US, i live in Australia and the seller did not really know that this unit only displays imperial. Is there any way to re program ...

...imperial system and not the metric which wouldn't affect the unit, just in the road signs, As in kms to someplace instead of miles like you are used to. As for the maps i would suggest that you buy ...