When the weight in the boat is uneven – you can lower one to flatten the boat. When you are running in a side or front quartering wave you can lift one side for a softer ride. In following waves you can put both down to “hug” the wave and reduce hopping – just don’t overdue it and push the bow too hard into the next wave. Finally going into the waves both down will keep the nose down and let’s the Deep V cut the waves better and again prevents hopping. Great option!