“Rocker” is the curve along the bottom of the board, from nose to tail. Some would say this is the single most important design feature of any board. Rocker determines how fast a shape will be, how easily it will turn, how well it will paddle and how well it will catch waves. While rocker is sometimes described in terms of maximum nose rocker (NR) and tail rocker (TR), the entire curve needs to be considered. Rocker is usually parabolic, which means the amount of curvature accelerates at both ends. Rocker is usually measured by placing a straightedge on the bottom, parallel to the stringer and touching (or tangent to) the exact middle of the board, lengthwise. The vertical distance from the tip of the board to the straightedge is the NR and the distance from the tail to the straightedge is the TR. Rocker can be further quantified as the measurements up and down the length of the board at regular intervals, say every six inches. Rules-Of-Thumb: Increased nose rocker allows for steeper take-offs and more vertical surfing. Decreased NR paddles easier and improves nose riding. Increased tail rocker makes a board easier to turn, while decreased TR makes a board faster.