Demos to Prepare:

Refraction & Total Reflection:
Aquarium.
Laser.
Lucite Rod.
Fiber Optics.
Two Liter light channel.
Mystery liquid invisible.
Wesson Oil, TT's in beaker.
Optical Disk, Prism & "Diamond".
Vernier Light Sensor:
candle.
flashlight.
incandescent light.
fluorescent lights.

Color:
Slide Projector and color slides.
Colored Floodlights
Color filters.
Color Wheel

Neat:
Penguins in Two Liquids.

So the fish appears to be higher than it really is, and the cat appears also to be higher as viewed from the fish.