Highly-skewed propellers are now standard equipment on luxury motor yachts, fast ferries, patrol craft and other high speed vessels where low noise and smooth operation are an essential feature demanded by todays sophisticated vessels. Particular care must be taken when designing this type of propeller to achieve the correct balance between the sectional thickness and the degree of skew. Usually manufactured in nickel aluminium bronze, the highly-skewed propeller is specially designed to suit the customers requirements. This type of propeller is often designed to comply with the rules of classification societies.