Stability is a function of just how much side to side motion and rocking you have when standing upright on the board and what amount of flotation a stand up paddle board has with your body weight balanced onto it. Length, width, and thickness all play a part on this. The better volume a Stand Up Paddle Kauai provides, the more stable it's certainly going to be. Volume is not necessarily the only component. A wider board will probably carry much more surface area across the water and is also much less likely to fall over.