Overview The FCS II JS fin was designed by world-renowned shaper Jason Stevenson (JS Surfboards) and delivers a smooth ride with an emphasis on flow and drive. “What I like about this fin is just the speed and flow that it has, then if you want to push it a little harder it has the release too. To put it simply, it’s just really reliable”. Jason Stevenson Ideal Conditions Open face, down-the-line waves, particularly good in point and reef breaks. Board Types Designed to fit the FCS II Fin System. Performance boards with deep concaves and moderate-to-extreme rocker. Fin Family Carver: Find Power. Powerful, drawn-out turns with added hold.