Outline and Foil are two basic properties of a surfboard that work closely together. This relationship is what draws an individual toward a surfboard – as in the general appearance and feel of the board under the arm. Within these elements are tail shape and the general dimensions of length, width, and thickness which constitute volume. This is what you are dependent upon for paddling and riding the board. Every surfer should take the time to get to know what measurements work for them including nose and tail width. Foil is the thickness distribution throughout. As you run your hands along the rails from nose to tail or across the fins, you can feel the change in shape and thickness. These changes should feel smooth and seamless. The purposes of foil are flotation, strength, flex, resistance and flow. Foil has a lot to do with a board’s paddling and initial speed into waves. Outline is critical to the type of wave you are surfing. It provides the proper planning area and the overall feel of a board. The location of the wide point in relation to the center of the board is important. Generally speaking, the wide point is behind center in most short boards. This creates a loose feeling in the back half of the board which is critical to surfing smallish conditions. In contrast, equipment for larger conditions generally has a wide point toward or in front of center. This creates a straighter rail line leading into the tail which gives a more drawn out feeling with the looseness toward the middle of the board. Other outline characteristics include the use of hips and wings in the fin area, which have become standard. This break in the outline creates a pivot point that loosens the board from rail to rail. When it comes to creating different types of surfboards such as twin fins, fishes, single fins, and short thrusters, theories change and the location of the wide point will vary for each. It’s all about figuring out where to place the volume to get a particular design to paddle, carry speed, and hold through turns. How the width and thickness move through the board becomes increasingly important as you go down and up in length.