The CSU-F is designed for riding big, heavy, barreling waves where you want to paddle fast, get barreled while still being able to turn in steep and open pockets. Based off the original CSU design Glenn Pang worked with Billy Kemper to add the perfect amount of foam in all the right places to allow for charging heavy waves on smaller than expected boards. Tested in places like Pipeline, Backdoor, Sunset and Teahupo'o, Billy was able to refine what works for max confidence when the waves get serious. Grab one of these if you feel like charging.