Rainbow Bonzer Center Fin 6.5"
The Bonzer fin was concieved by the Campbell brothers, Duncan and Malcom of Oxnard California,in 1969. The brothers were tired of the limitations they found with single and twin fins (single fins not being loose enough and twin fins being too loose. Bonzer fins were originally a triangle shape and were designed out of a passion for speed and maneuverability. Designed to fit on Bonzer boards which boasted the first single to double concave (which you now see on most thrusters used in professional competitions) based on Jacob Bernoulli's principle, the Venturi effect. The double barrel concave inside of the side fins creates an area of low pressure so the high pressure water under the front third of the board is drawn to the low pressure area jetting the water through the concaves and out the back creating speed. These Bonzer fins are more rounded than the original shape and the more fluid template makes for increased turning capability. The center fin is used with 4 side fins to set up a 5 fin Bonzer (arguably the best of the Bonzer options). The side fins are where these boards get their speed while the center fin has been tweaked over time to create the perfect compliment to the side fins. So if you like to go fast, get a bonzer.