The more extreme the conditions the more extreme the curves and contours can be. A bit of extra rocker and concave will help keep you in the most critical parts of the wave and fit best when on a steep face. Longer and more pulled in outlines hold when the waves are big and the right amount of volume makes paddling and catching the set waves much easier. If you are looking for a board that you can charge the big stuff on, it is always important to work closely with the shaper to get just the right design. There is nothing more frustrating when the waves are pumping and you are under gunned or simply riding the wrong surfboard for the conditions.