There are several different grades of aluminum that are suitable for marine conditions. Marine grade aluminum, for the most part, is limited to the 5XXX and 6XXX grades. Grade 5052 is an excellent marine grade for when formability is required. If strength is more of a concern, grade 5083 is a good alternative. 6061-T6 is an all-around popular grade of aluminum that is also commonly used in marine applications. It has very good corrosion resistance and is precipitation hardened. These grades, for the most part, have additional chromium and manganese to help protect them from corrosive marine conditions.
Applications: structural shipbuilding, boat hulls, boat lifts, docks, and other offshore structural applications