h solids or liquids, why can i 'see' the fish, the bottom, the rocks, thermoclines and other stuff. those are solids and liquids, right? right. i dont want to change everyones way of thinking, but actually the sound does not really 'bounce' off objects and come back. in a nutshell, the sound changes speed when it hits objects of different density-like passing thru water and then thru a rock. diffe