Introduced by the indomitable Blondie Hasler, founder of the OSTAR solo transatlantic race in 1960, the original sailboat windvane consisted of a direct coupling of a horizontally rotating (vertical axis) vane to a trim tab on the aft edge of a transom-hung rudder. Once the vane was fixed to the desired angle off the wind (using a round base plate with notches spaced at 5-degree intervals), any course change rotated the large vane like a weathercock. This in turn twisted the tab to one side of the main rudder, driving the rudder in the opposite direction, thus bringing the vessel back on course. The advantage to this system was its ease of construction and low cost, but it was best adapted to the waning style of transom-hung rudders. Also, a large vane was required to harness sufficient wind to power the trim tab. Therefore, especially in light airs, the tall, heavy vanes often reacted more to the yaw and roll of the vessel than to the wind, resulting in erratic meandering.