Where is the Fish? A Refraction Simulation

I have seen a few simulations for apparent depth but was not satisfied with them. So I created this from scratch for use in tomorrow's lesson. The positions of the eye and image of the fish are adjustable. It is more challenging to design for the actual fish to be draggable, so I only could allow the image to be dragged and hence, use it to shift the position of the actual fish.

Direct link to the applet: https://www.geogebra.org/m/kdszgpfg