The upper limit of coral reef growth along the coast is limited by the level of low tide. Corals cannot survive more than brief exposures out of the water. Therefore, tidal conditions contribute to the size of a coral reef.
Corals continually build new calcareous rock structures on top of old ones, a process which extends the reef seaward toward deeper water and upward toward the surface. Algae live in the tissues of the coral and supply them with food, while the corals in turn supply the algae with shelter and nutrients. This symbiotic relationship contributes to the corals' need to remain submerged.
Water temperature and wave conditions are also key factors in reef development, while tidal conditions influence the height of coral reefs.