What To Know About The Shape Of A Surfboard

The word „Shape“

Shape refers to the form of a surfboard in all dimensions:

• Rocker Line
• Tail Rocker
• Nose Rocker
• Outline
• Shape of the Nose
• Shape of the Tail
• Deck
• Board Thickness

When it comes to evaluating the shape of a board, it’s important not to make judgments based solely on one component – all aspects contribute to the performance. For non-professionals, it is generally advisable to opt for a well-balanced shape as it tends to offer a good performance.

Rocker / Rockerline / Nose Rocker / Tail Rocker

By taking a side view of a surfboard, our attention is captivated by the curvature recognized as the rocker line. The rocker line refers to the entire bottom curve of the board, often referred to as the scoop rocker line. The upward curve at the front is called the nose rocker, and the downward curve at the back is called the tail rocker.

In order to prevent sudden deceleration of the flow at any point, efforts are typically directed towards constructing seamless transitions along the rocker line. However, there are significant differences. There are shapes with a continuous rocker line, meaning the bottom curve distributes evenly between the tail and nose rocker. But there are also shapes with a discontinuous distribution, where the bottom curve distributes unevenly, for example, with a strong curve in the nose area and then transitioning into a largely flat area.

Rockerline design for flat water

Surfers who desire to smoothly ride on calm water without wind waves should consider using a board that has a flat rocker line, minimal nose rocker, and little tail rocker. This design helps minimize resistance from the water. However, when dealing with medium to large choppy waves with wind, a board with more nose rocker is recommended. This design helps with stability and maintaining speed when surfing at a steep angle to the wave.

Rockerline design for waves

In simpler terms, if the wave is steep and you ride aggressively, your board should have more rocker. A board with a lot of nose rocker helps with entering the wave, while pronounced tail rocker and appropriate tail design improve maneuverability and allow for tight turns.

Outline

The term „outline“ pertains to the silhouette of a surfboard when seen from above. It decides the board’s width and how it is spread across its length. The outlines of various surfboards differ considerably, depending on their intended purpose.

Rail and Railform

The surfboard’s rail refers to the board’s outline edge from the nose to the tail. The cross-sectional view of the rail differs depending on the shape and thickness of the board. The rail’s shape and thickness also vary along the outline, with common forms being round rail, down rail, and mixed or oval shapes.

The board’s rail serves as a guide for the water and has a considerable impact on its maneuverability during turns and planing. Additionally, the rails play a role in the board’s buoyancy.

One common way to shape a surfboard’s rails involves starting with a thinner, circular rail near the nose, gradually increasing the thickness towards the middle to improve buoyancy, and then tapering down to a sharper rail near the tail to enhance maneuverability when turning.

Nose

The term „nose“ refers to the front section of a surfboard and there are two main designs: a pointed nose found on wave boards and a round nose found on most all-round boards. The shape of the nose also affects the width and volume distribution of the board. A round and wide nose is ideal for easy wave entry, stability, and is recommended for beginners. For nose riding in waves or maneuvers on flat water, a wide nose is essential.

In contrast, a slender and tapered nose results in greater curvature at the front of the board, leading to improved manageability, particularly in challenging waves, and increased agility.

Tail

The board tail is the back of the board. There are different tail shapes and variations. The most common ones are the squash tail / square tail (straight finish), the round tail (tapered), the pin tail (pointed), the diamond tail and the swallow or fish tail.

The rear end of a board is referred to as the board tail, which can come in various designs and forms such as the straight-edged squash or square tail, the tapered round tail, the pointed pin tail, the diamond and the swallow tail.

In flat water, the differences are minimal in surfboards. A straight edge like the squash tail has slightly less water resistance, while a round tail is better for maneuvers like the pivot turn and easier to control.

In waves, the tail shape has a significant impact on the riding characteristics. The square tail or its variation, the squash tail offers agility and, thanks to the slightly wider tail, additional buoyancy that keeps the board fast. On the other hand, the round tail provides more guidance and is particularly suitable for wider turns. The swallow or fish tails combine the best of the rounded pin and squash tail. The V-shaped gap in the tail enables water to flow smoothly between the two pins, resulting in a better grip when transitioning from one rail to another during a wave turn. As a result, the surfboard gains more control and direction when riding the wave. The V-shaped tail, like that of a fish, aids the surfer in navigating through rough or turbulent waves more easily.

The diamond tail is not as frequently seen as other tail shapes. It is similar to the squash tail, but the corners are angled to create a diamond shape at the back of the board. This design enhances the board’s maneuverability, making it easier to turn than a typical squash tail. Additionally, it has an eye-catching appearance that results in a stylish board. It is suitable for both novice and intermediate surfers.

Thickness

The thickness of surfboards varies greatly from tail to nose, and the distribution of thickness has a significant impact on the riding characteristics.

Having a slightly thicker and more voluminous tail can facilitate entering the wave. Nonetheless, it is erroneous to assume that having more thickness is always beneficial. If the thickness is distributed unfavorably and excessively, the board can feel like a cork, which can make it hard to manage, particularly in waves.

Width:

When discussing board width, there are various specifications to consider. Typically, this pertains to the widest part of the board, especially when only one width measurement is provided in inches. In the realm of custom-made boards, additional width specifications may be included to offer more details about the tail and nose width. Measurements are taken every 12 inches from either the nose or tail.

For examfple: 21 ¾“ , of Nose 18 ¼“ , of Tail 15 ½“

Bottom:

The term „Bottom“ in the world of SUP or surfboards refers to the underside curve of the board in cross-section. Different shapes include Concave (curved inwards), Double Concave (double curved inwards), and V (V-shaped like a ship’s hull). These bottom curves are often combined, such as Single to Double Concave, which features a wide concave in the nose transitioning into a flat area and then splitting into a double concave in the tail.

Deck:

The top side of the board is known as the deck, offering a variety of design shapes. One popular option is the domed deck shape, which helps water to flow off smoothly. This, combined with the rail shape, prevents the board from digging into the water during turns and enhances overall handling.

Outline

The outline of a SUP board is defined as the outer hull line. Key characteristics include the positioning of the widest point (measured from the tail) and the overall shape of the outline.

When the widest point of the board is placed closer to the tail:

This trait is commonly found in small waves, making it ideal for quick turns and maintaining speed in faster waves.
It also helps to maintain speed in fast waves while riding.

A rather straight outline makes the board:

Ideal for tackling large swells, perfect for executing extended turns while maintaining optimal control.

Smaller boards are something for:

These boards are specifically designed for experienced surfers, rather than beginners entering the sport.

The wider the board is:

the easier to ride.

The shorter the board:

The better it turns, simple as that!

Tail:

The tail shape, specifically the outline of the tail, is known as the tail. It is part of the overall outline of the board, with common shapes including pintails, rounded pintails, squaretails, squashtails, and more unique shapes like swallowtails.

Tail shapes of surf boards:

What purpose do squaretails, squashtails, and rounded pintails serve? Primarily for wider boards that need a tail that fits the design seamlessly. Rounded squaretails are typically used.

Where are classic pintails and rounded pintails commonly seen on surfboards? These tail shapes are commonly seen on boards used in larger waves, requiring a narrower tail like a classic pintail or gun pintail.
Mostly for wider boards. Such boards require a corresponding tail that can be seamlessly integrated into the overall concept. Rounded squaretails are usually shaped.

„These tail shapes are often found on boards that are ridden in larger waves. They require a narrower tail, so a classic pintail – if not a „gun“ pintail.

Scoop-Rocker-Line

The Scoop Rocker Line refers to the shape of the centerline of the underwater hull of the board.

Different Scoop Rocker Lines of Surf Boards:

Scoop, the curvature of the Scoop Rock Line towards the nose, is measured in centimeters. A greater Scoop reduces the risk of the nose digging in, particularly in waves, but excessive Scoop can decrease dynamic lift.
The larger the Scoop, the:
„The lower the risk of the nose digging in, which can happen especially in waves. On the other hand, too much Scoop reduces a lower dynamic lift.“

So, if the scoop is only small?
Then the board can nose dive!

The curve of the scoop rocker line rising towards the tail, known as rocker, is measured in centimeters. Surf boards with minimal or no rocker are found rather in windsurf boards. A flatter bottom curve is only present in the central area where the rider stands. An upward curve at the tail is essential for smooth water flow. Lack of rocker would create more water resistance.

 boards with more rocker („with a larger rise at the tail“):

These boards turn better, with the entire bottom curve needing to be harmoniously shaped. And just having more rocker alone is not enough.“

Rails

The edges of the boards are called „rails“. The shape is the expression.

We look at the widest point down to the underwater hull. A full and further inward shape is called „tucked-under-edge“. Race boards have no or only a slight tucked-under-edge. Rail shapes with more tucked-under-edge provide more reaction in turns. In other words, it becomes easier to turn.

The main features of railshapes in freeride, wave, and race boards:

In general, maneuver-oriented boards have thinner rails with a lot of tucked-under edge. This is a clear requirement for wave boards. A rail here should be forgiving and have good responsiveness.

For race boards, you need a fuller rail that is also high and steep. This supports propulsion in such boards.
For freeride boards, we are somewhere in between in terms of this shaping feature.

Bottom:

The bottom refers to the shape of the board in cross-section. Basically, there are flat, „V“, concave, double concave, and triple concave underwater hulls. There are also subforms such as „bevels“. The most prominent bottoms are „V“ shapes.

Nowadays, every board has a „V“ somewhere in the underwater hull. We speak of a „V“ when the centerline is deeper than the outer hull line.

Certain types of „V“ allow for faster turns. If too much „V“ has been shaped into it, then it makes the board unstable, i.e. as shapers, we have to find a compromise.