Ah yes, Snell's law. You get to play with that one a lot in physics and geometric optics classes. Grizz, your law of shooting low by 8"doesn't hold up because it doesn'ttake into account how far above the water you (your eye)is so your rule of thumb is not correcta lot of the time, but the idea is correct, Aim low and if the fish is deep, then aim even lower andif you're like me, you'll still shoot over the fish.ha. Check out this site and take a look at the model towards the bottom. In the top field, leavethe mediaas air and thenclick on water forthe bottom media. Now move the flashlightalong the arc and you can see the difference as to where it will appear. Remember if you are shooting straight down at the fish, then hold right on independent of how deep he is. The model will display what I am talking about.
http://www.ps.missouri.edu/rickspage/refract/refraction.html