Is there a method I have read about on here to determine the depth of a pond using a bobber (float) and a rod and reel? From the bank.
Slip bobber with enough weight so it will sink the bobber if the bobber hits the knot before the weight is on the bottom. Keep adjusting the knot further and further up the line until the bobber floats, then measure that distance
Those castable depth finders are good, but I don't know how far of a transmitting range they have. But, if the pond isn't large, that point might be moot.