Fins are what you we rely on to carry us through moves and out of intense situations. When choosing fins, you should take into consideration your weight. Most people use a thruster set with a base between 4.5 and 4.75”. The side fins generally range between 5- 7 degrees; the straighter up and down, the stiffer; the more leaned out, the looser. Location of the fins, how they are secured, and the amount of tow is perhaps more important than minute changes in the template. From a performance standpoint the fins should either be glassed-on or fit into a fin system firmly at the base with flex at the tips. Fiberglass fins have always worked better than plastic. They require less thickness and weight, and produce a more favorable flex pattern.