Thread: Castable depth finders?

With all of this talk about pier depth, I was wondering if any of you have started using any of the new castable sonar units either to look for fish or for depth changes? They seem to be very popular for bank fishermen.

In freshwater I've used them but find little I can't find out about bottom contour by fishing because resolution is low. What makes sonar on a boat useful is the boat -- sonar plus boat equals covering ground more efficiently. If you've got one already, by all means try.