Place the four inch sea creature in a full plastic bottle of water (follow directions included with diver). Squeeze and hold the sides of the bottle and watch as the sea creature dives down. Release the bottle and watch the sea creature float back to the top. This experiment is based on water pressure and will bring hours of enjoyment to you and your children. One liter and 2 liter plastic pop bottles work best with the sea creature diver. Bottle and water not included.