By Janice VanCleave (John Wiley & Sons,1996). Learning about the ocean and its inhabitants becomes an intriguing adventure. Use a bottle, pennies, a straw, and clay to demonstrate how submarines rise. Make your own wave holder with index cards and a plastic folder. Through these and other activities you'll find out how fish move up and down in water, how pollutants move into the ocean, how to navigate without a compass, how to map the surface of the ocean floor, and much more.