A SHOAL is a shallow area of water, usually found in the ocean, that is composed of sand or other sediment. It is typically located near the shoreline and is often visible at low tide. A SHOAL can also be referred to as an underwater sandbank. This type of formation is created by the movement of waves and currents, which deposit sediment in the shallow area. Shoals are important habitats for many species of fish and other marine life, providing them with shelter and food.