Marine propeller with winglets and method of design thereof

A propeller for a marine propulsion device, the propeller comprising:

• a hub extending along an x-axis;
• and
• a plurality of blades, each blade in the plurality of blades having a blade root non-pivotably attached to the hub and extending radially outwardly from the x-axis toward a respective blade tip;
• wherein each blade in the plurality of blades comprises a y-axis extending radially outwardly from and perpendicular with respect to the x-axis;
• wherein each blade in the plurality of blades comprises a z-axis extending perpendicularly to both the x- and y-axes;
• wherein each blade in the plurality of blades comprises a plurality of winglet sections proximate its blade tip, the plurality of winglet sections beginning at a given radial location on the blade and ending at the blade tip, wherein the given radial location on each blade is between about 90% to about 99% of a radius of the propeller;
• wherein each winglet section in the plurality of winglet sections of each blade is rotated about the blade's z-axis such that the blade tip is offset between about 1 degree and about 90 degrees from a surface of the blade that is radially inwardly of and adjacent to the given radial location;
• and
• wherein the blade tip of each blade is rotated about the blade's z-axis by between about 1 degree and about 5 degrees.