The outline of a surfboard is a major influence in how your board performs, and also assists in classifying which design type it is called.
The outline refers to the shape of your board, or the result of rail lines coming together to direct water flow. This shape then interacts with variances in noses and tails.
This outline will then determine how the board performs in terms of hold, turns, and speed.In general, board outlines fit under the three categories of: parallel, curved or hybrid.
A parallel outline is more stable in a straight line, and is mostly utilised in boards that want long, drawn out turns. It’s not uncommon to see this outline in logs and fishes, such as the Diverse Style Commander, because the shape has more surface area on the underside of the board.
A curved outline refers to the continuous curved shape from nose to tail, which is commonly found in shortboards, such as the Dahlberg Rocket Rod. A curved outline is ideal for creating tighter turns as they are less stiff than a parallel. This outline is often combined with a lower or flatter rockers.
A hybrid outline is a board that features both curves and parallels throughout its overall shape. A general example is a board that features strong parallel lines through the widest point, which then moves into curves throughout the nose and tail, as seen in the Diverse Astral Tracer.
A hybrid outline creates versatility, with curves that guide you through turns, but lines that provide you with speed.
There are so many elements that affect a boards performance. It is the combination of these elements to get the desired effects you are looking for in a board that is the trick.
Surfboard shapers have to think about how each of these elements work on their own in order to combine them with others to get the results they are looking for. A curvier outline combined with a flat rocker gets a board that is fast yet turns well. And in that particular case, those are only two of the many other elements that will be in that particular board. Different concave configurations, the overall width of the board, the general nose and tail shape, the thickness and foam distribution, surfboard volume and many more all contribute.
That’s what makes surfboards and surfboard design so amazing.