HO Proton Kneeboard (2027)HO Proton Kneeboard Starting out on a kneeboard? The Proton gives you the confidence to find your balance and nail those first runs behind the boat. As you get more comfortable, you'll discover how responsive it becomesthe board rewards your improving technique with smoother turns and better control. The retractable fins are your secret weapon. Keep them down when you're building foundational skills and need extra grip, then flip them up as you