THE MOST COMMONLY USED materials for construction of piers and docks are reinforced or prestressed concrete, steel, and timber. Composite materials are used primarily for mechanical applications such as pipe hangers and railings, but the use of composite materials in structural applications such as piling and gratings continues to increase. Other metals, primarily stainless steels and aluminum alloys, are often used for mechanical applications and fasteners. The primary criteria for selection of materials for marine piers and docks are past experience, cost, and availability. However, corrosion testing is used to evaluate candidates for many specific applications. This testing is commonly in the form of the evaluation of either full-scale or subscale components, but direct testing of base materials is also performed in many cases.