Can these go on any SUP? I have two, both with rigid fins (a tahoe bliss and a SUP ATX). The lake we bought a place on has a lot of underwater stumps, and hitting one sure takes the mellow out of my paddle. Thanks-Karen

fins unlimited box
Yes, The box is standard on all SUP’s. It is called a fins unlimited box and they became standard on surfboards in the late 60’s. Prior to that there was a lot of diferent box systems that didnt crossover. The flex fins are a great idea for shallow areas but performance wise choosing the perfect fin is a matter of trial and error. There are many fin manufacturers and hundreds of handmade fins that you can try in your box.