The subtidal zone is the area below the low tide water line. The vast majority of this area is submerged most of the time, and it includes an array of habitats. Submerged aquatic vegetation beds and coral reefs reside in the subtidal zone.
The organisms that live in the subtidal zone range include eel grass, algae, starfish and shrimp, as well as a myriad of other creatures and flora. Crabs and dolphins may also live in the subtidal zone. In some areas of the world where the water is fairly clear, such as in Alaska, the ocean floor is visible up to 100 feet in depth.