The outline of a surfboard is the distribution and configuration of the surface area of the surfboard. This layout is referred to as the plan shape or the template of the surfboard.
Outlines are often referenced by the configuration of specific elements of the surfboard: the tail (roundtail, roundpin, pintail, squash tail), the relative width of the surfboard (narrow board, wide board, narrow nose with wide tail, full nose with tear drop tail.)
These descriptions state the obvious identifying features of a surfboard's plan shape or template, descriptions that are useful for discussion and the design of the surfboard's outline. These features are design variables that surfers, shapers, and designers use to create, modify, and tune (dial up or down) specific performance features in a surfboard.
Outlines may also be referenced by the overall distribution and configuration of the surface area of the surfboard. Considering the surfboard's outline from this perspective has significant impact on the design process and the performance of the surfboard.
This perspective focuses on the fundamental and essential effect of the overall view of the outline on the design goals of the surfboard. Specific elements of the outline (nose and tail configurations and width throughout) are incorporated into the design to further develop and tune the surfboard's outline. The logic is to begin with a fundamental design goal, basic, relevant, and essential, then tune that fundamental design with specific elements.
Distinct overall outline configurations include dominantly "parallel" outlines, dominantly "continuous curve" outlines, and "hybrid" outlines (where parallel and continuous curves are integrated to mix and match their effects on the performance of the surfboard.) These overall outline descriptions, like the specific elements of the outline, are important design variables used to create, modify, and tune the performance of the surfboard.
Surfers, foamsmiths, and designers may prefer either of these approaches or perspectives (or others) to initiate outline design. Arguably, though, initiating the outline's design with relevant choices about performance based on the overall distribution and configuration of surface area then tuning the outline with specific elements ultimately yields a superior surfboard.
Overall Distribution and Configuration of Surface Area
Parallel outlines feature elongated nearly straight curves in the plan shape or template of the surfboard. They are common to all classes of surfboards and are most functional when modified and matched with areas of continuous curve strategically integrated into the outline.
A parallel shortboard, semi gun, tow board, hybrid, or longboard outline will have strong nearly straight curves in the template running "parallel" to the center line of the surfboard. These parallel lines dominate most of the length of the surfboard. They extend surface area further into the nose and tail of the surfboard. They can be very effective in creating a longer drawn out turn from a shortboard, small semi gun, or tow board when required by surfing conditions. (Adjustments to other design variables are required to keep the most extreme of the parallel outlined boards from being to stiff or not quick in a tight situation.)
Extreme parallel outlines can be problematic for shortboards. as they may lack the necessary curves required by a shortboard to turn and release in tight and critical as well as flat and soft sections of waves. Strategically placed parallel lines through the widepoint (near the surfer's front foot) towards the fins (just forward of the surfer's rear foot) matched with continuous curves near the rail fins provides the required release and tight radius a shortboard needs to profit from the speed and power provided by those parallel lines. Dominantly parallel outlines may be used in semi guns and hybrids where the length of the surfboard matched with the elongated straight curves yields a long powerful turning radius. The extra length of these surfboards remains an asset when, as with shortboards, the parallel areas of the template are matched with areas of continuous curve. See "hybrid outlines."
Parallel outlines are very common to longboard templates. Classics, nose riders, and "pigs" have "parallel" lines dominating the nose and widepoint of their outlines. Their dominant parallel lines promote down the line trim and nose riding performing these tasks best when well positioned in the most critical parts of waves. These surfboards are designed for their outstanding trim and nose riding, not to be mistaken with a design priority of turning or carving a tight powerful radius.
Contemporary and performance longboards have strong parallel lines in the widepoint and midsection of their outlines carrying to a lesser degree into the nose and tail than they do in "old school" longboards. The shorter parallel lines matched with smooth sweeping curves into the nose and tail of the "new school" longboards creates an outline that has a unique combination of trim, nose riding, and turning potential.
Continuous curve outlines
Continuous curve outlines feature smooth, geometric (nearly elliptical), constant curves in the plan shape or template. They are common to longer shortboards, semi guns, and hybrids where one of the fundamental design goals is an easier tighter turning radius turn from a surfboard whose extra length would otherwise result in the surfboard's performance being relatively "stiff." Another common use of a continuous curve outline is matching it with a flatter more relaxed rocker profile in an average shortboards and hybrids. (When a flatter rocker profile is essential to the design goals of the surfboard or the preference of the surfer.) The curved outline matched with flatter rocker yields a surfboard that maintains acceleration and drive out of the turns and can still carve a very tight radius turn.
"Hybrid" outlines feature combinations of strong parallel lines and smooth continuous curves in the distribution and configuration of the surface area of the surfboard. They are common to all classes of surfboards. (Shortboards, semi guns, big wave guns, tow boards, hybrids, funboards, and longboards.) Typically, these outlines have parallel lines in the widepoint of the surfboard carrying forward towards the nose and aft towards the hips and tail. An elongated continuous curve carries the plan shape or template into the nose and a shorter curve or "hip" carries the outline into the fins and tail. This curve or "hip" may continue through the tail or straighten into the tail depending on the preferred performance goal of the surfer, shaper, designer. Matching various types of curves in the surfboard's outline arguably yields a very versatile and functional outline. This is the expected result of using the most functional and relevant curves as an appropriate response to the performance requirements and the other design variables (rocker, bottom contours, foil, rails, and fins) of a surfboard. (The performance requirements of the surfboard are a product of the skill of the surfer, the range of conditions it will be used in, and the intent of the surfboard's design.)
Outlines Referenced by the Configuration of Specific Elements
All these specific tail configurations may be applied to parallel, continuous curve, and "hybrid" outlines. Surfers, shapers, and designers should chose the most appropriate combinations to render the outline relevant to the design goals and intended use of the surfboard. See tail.