Open an empty shoe box. Place the lid upside down on a table. Insert the open shoe box into the lid so that the open box mouth faces to the side, creating a cave area for the ocean world.
Tape the lid to the shoe box body, preventing any separation between the two pieces. Cover the inside and outside of the shoe box with blue construction paper using tape or glue.
Decorate the shoe box background with drawings of scuba divers, fish or even whales. These drawings create depth to the shoe box project scene.
Fill the cave's floor (the box lid) with sand. Choose dark, black sand for deep ocean scenes and lighter, beige sand for tropical regions.
Form plant life with clay. Use varying colors for creating corals; construct seaweed from green clay. Place the clay forms into the sand and press down onto the lid below. The clay should stay upright from the surrounding sand support and the adhesion to the lid.
Cut out sea animals from magazines or draw them from scratch with crayons or markers. Tape the animal forms onto cardboard that is cut in the same animal shape.
Tape a piece of fishing line to the back of the cardboard animal. Tape the other end of the line to the top interior of the shoe box. The sea animal should look like it is "swimming" as it hangs inside the shoe box. The fishing line is virtually invisible, making the ocean scene more realistic. Add many different animals to the scene, as desired.