The use of aluminium alloys in boat building is largely based on their multiple excellent properties, which make them an important material choice in the boat building industry. Aluminium alloys are used in a wide range of ship types, including yachts, speed boats, cargo ships, fishing vessels and special ships. The use of aluminum alloys in the design and manufacturing process can improve the performance and economy of ships and promote the further development of the shipbuilding industry.

Aluminium alloys used in the boat building industry commonly include 5000-series (e.g., 5052, 5083, 5086, 5456, etc.) and 6000-series (e.g., 6061, 6063, 6N01, etc.), as well as some 7000-series (e.g., 7004, 7005, etc.) alloys. These marine grade aluminum alloys are widely used in hulls, decks, compartments and other structural components due to their excellent corrosion resistance, good welding properties, moderate strength and good processability, which can effectively enhance the performance and economy of ships and extend their service life.

The following are specific reasons for why are aluminum alloys used in boat building:

- Excellent corrosion resistance:

After reacting with oxygen, aluminum alloy will form a stable and dense film of aluminum oxide on its surface, which prevents it from further reacting with the surrounding environment, thus providing excellent corrosion resistance.

This property of aluminum sheet for boat building is particularly important in marine and humid climates, where it slows down the rate of corrosion and extends the service life of equipment such as warships and submarines.

- Low density and light weight:

Aluminum alloys have a relatively low density, only about one-third that of iron.

With the same hull size, a boat made of aluminum alloy will be lighter, which helps to increase the ship's top speed as well as fuel economy, resulting in a longer range on the same amount of fuel.

- Good welding properties:

Aluminum alloys have good weld crack resistance, with little difference in the performance of the welded joints after welding.

This makes aluminum alloys easy to weld during the shipbuilding process, and the strength of the welded joints can meet the requirements of ship use.

- High strength and rigidity:

Aluminum alloy has high strength and rigidity despite its low density.

This makes aluminum alloy able to meet the requirements for structural strength and rigidity of ships during navigation.

- Good processability:

Aluminum alloys are easy to be processed by extrusion molding and casting, which makes aluminum alloys flexible to be applied to the manufacture of various shapes and structures of components in the shipbuilding process.

- Economical:

The processing cost of aluminum alloy is relatively low, and due to its excellent physical properties, it is more economical to use aluminum alloy for shipbuilding.

In summary, aluminium alloy has been widely used in boat building due to its excellent corrosion resistance, low density and light weight, good welding performance, high strength and high rigidity, good processability and economy. These advantages make aluminum alloy one of the key materials to achieve ship lightweighting and improve performance.