Surface propellers are usually associated with cleaver style propellers. The leading edge is very sharp & the blade root is designed to withstand heavy alternating loads as more than half of the blade is out of the water at speed. The pressure face of the blade is generally concave, but it could be flat & the blade's leading edge will have a shallow entry angle. Since it is desirable to have this type of blade with a very thin section, it should be made of a material which can be hardened. This type blade will also have trailing edge pitch or cupping.
Rounded tip blades are intended for deeper applications where maximum thrust & low slippage are required. There features will be slightly opposite of a cleaver style propeller with respect to blade shape & blade thickness. Lifting or non-lifting abilities of either are determined by the amount of blade rake used. Low rake angles give high lift & high rake angles give lower lift. Both blades types could be used in a surface application.
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