To make a home that makes you feel as if you just went diving, hang up a tapestry, add corals and deep sea fish, and feature underwater . If you don’t want too much blue in your space, you should have a neutral wall and then decorate with starfish decor to accent your underwater, deep blue sea and create a perfect under-the-sea room. Featuring oceanic life is an amazing way to create, design an underwater schemed interior and show off the natural beauty of the ocean.