Put simply... this is the single most successful product our company has ever developed. We originally set out to design a propeller specifically for water skiing and the four bladed CompuThrust has exceeded our most optimistic expectations. The CompuThrust has four parabolic style raked blades of totally unique CAD/CAM design. The total blade area is about 40% larger than normal three bladed ski boat propellers providing enormous thrust for both social and tournament water skiing. The propeller is exceptionally smooth and it simply won't "let go" throughout the full RPM range.