In my limited experience I feel that hull design and seating location both play a role in how a kayak is effected by waves. A finer cutting bow and or a more forward seat location will help a kayak cut through smaller waves and will give the kayak a greater speed in these conditions. This same kayak when exposed to large waves will bury the bow in waves more, be harder to handle, keep on course and will loose some speed. A kayak with a fuller bow and or a seating location more aft will slap down when traveling over smaller waves and not be as fast but will ride over larger waves smoother, be easier to control and have greater speed. It's always a give and take depending on what you want out of a kayak. I have kayaks form each extreme and enjoy each kayak in the appropriate conditions.