Box rails, also known as square rails, are a common feature on many modern surfboards. They refer to the boxy, rectangular shape of the rails along the edges of the surfboard. Rails play an important role in how a surfboard handles and performs in the water. Understanding what box rails do can help you choose the right surfboard shape and design for your surfing needs.
What Are Rails on a Surfboard?
The rails are the edges that run along the outline of the surfboard. They connect the widest points of the board from nose to tail. Surfboard rails can have different shapes – some are more rounded or curvy, while others have a more angular, boxy shape.
Rails affect:
- How the board catches, rides, and releases waves
- The grip and hold the board has on the wave face
- The directional stability
- The turning ability
By altering the rail design, shapers can fine-tune the performance characteristics of the board. Box rails create different lift, drag, and flex patterns compared to rounded rails. The rail shape works together with the rocker, bottom contours, fins, and other elements to influence how the board handles.
What is a Boxy or Square Rail Shape?
As the name implies, boxy or square rails have a straight, box-like edge with sharp corners rather than a rounded shape. This angular rail first became popular during the shortboard revolution in the late 1960s. Many of the high-performance shortboards of the time featured a blocky, rectangular rail shape.
Today, box rails come in different sizes and degrees of sharpness. Some have a fuller, wider rail while others are thinner and more rigid. The boxiness might be focused more towards the tail or evenly distributed from nose to tail. Certain big wave gun boards have boxy rails to help dig into steep, powerful waves.
How Do Boxy Rails Affect Surfboard Performance?
In general, square rails make the board feel more responsive and loose. The sharp edges provide less surface area and decreased drag compared to rounded rails. This allows the surfer to easily pivot, slide, and change direction on the wave.
More specifically, boxy rails:
- Increase grip – The sharp corners “stick” into the wave face better and resist sliding out.
- Enhance rebound – The rigid edges produce added spring or bounce off the water.
- Improve release – The decreased surface area lets the board shed water and reduce drag when maneuvering.
- Add liveliness – The board feels looser and more responsive due to less damping from drag.
- Promote sliding – The angular shape allows the rails to slip and break free from the wave.
- Provide directional stability – The rails hold a firm line through turns without wobble.
In choppier surf, the square shape also helps the board cut through the bumps and disturbances. Overall, boxy rails make the board feel fast, loose, and responsive. The crisp edges provide a tight, precise feel compared to a rounder rail.
Advantages of Boxy Rails
Here are some of the potential benefits of boxy rails on a surfboard:
- Increased maneuverability and turning ability
- Enhanced speed and acceleration
- Good grip without overly “sticking” to the wave
- Precise rail-to-rail transitions
- Looser, snappier release off the top of waves
- Added projection off the wave lip
- Easier to generate and control speed without rapid deceleration
- Stable platform for aerial maneuvers
- More radical vertical attack is possible
Box rails allow more aggressive, high-performance surfing. The board reacts instantly to the rider’s inputs. The stiffness provides a connected feel between the surfer and the wave. Overall, square rails lend themselves well to modern maneuver-focused surfing in good quality waves.
Disadvantages of Boxy Rails
The main drawbacks of boxy rails include:
- Less forgiveness – The rigid edges are less forgiving of errors. The board can feel more difficult to control for less experienced surfers.
- Demands more input – It takes more nuanced footwork, balance, and positioning to get the best from square rails. The feel can be too responsive for some.
- Can feel unstable – In marginal or mushy surf the board may seem to lack directional steadiness compared to a rounded rail.
- Requires better technique – To avoid slipping out, the surfer’s rail technique must be on point, especially on steeper waves.
- Harsher ride – The angular rails don’t absorb chop and disturbances as well, resulting in a harsher, bumpier ride in rough conditions.
In general, boxy rails perform best for skilled surfers in good quality surf. The crisp responsiveness can be difficult for beginners to control. The fast release is not ideal on soft crumbly waves either. Rounder rails may provide more user-friendly characteristics.
Different Types of Boxy Rails
There are a few variations of boxy rails that feature slightly different dimensions:
- Standard box – The rail has a medium width and fairly sharp corners. This provides a balance of grip, slide, and precision.
- Full rail – A wider rail with more surface area and slightly rounded corners. Adds more drive and hold than a standard box shape.
- Hard rail – A thinner, more rigid edge with very sharp corners. Maximizes responsiveness and release off the wave.
The wider the rail, the more drive and control it will provide. Thinner rails feel looser and more maneuverable. Box rails may be combined with other rail elements like channels and hip tail kick.
How are Boxy Rails Created?
Shaping boxy rails requires precise tools and techniques. First, the shaper machines the blank foam core to achieve the basic outline. Next, they use planers and surforms to hand shape the square edge. Sanding blocks are critical for getting crisp, straight corners.
After the rail shape is formed, the board goes through the remainder of the shaping process – deck contouring, fins, glassing, and polishing. Advanced composite materials are often used to reinforce the boxy rails so they can withstand heavy surfing forces without chipping or denting.
Do All Surfboards Have the Same Rail Style?
No, rail shapes vary widely on different types of surfboards. Here are some general guidelines:
- Shortboards – Tend to have thinner, boxy rails for responsiveness.
- Longboards – Often feature thicker, rounded rails for smoothness.
- Funboards – May combine semi-boxy rails near the tail with rounded rails towards the nose.
- Grovelers – Designed with boxy or semi-boxy rails to help penetrate soft, mushy waves.
- Hybrid shapes – Mix different rail profiles to balance speed, hold, and slide.
- High performance boards – Aggressively boxy rails maximize speed and snap.
- Big wave guns – Full, boxy rails provide control in huge surf.
The rail design aligns with the intended use for each board style. But there are always exceptions. Some longboards have boxy rails or shortboards have rounded rails. Consulting with a knowledgeable shaper can help determine the ideal rail shape for your goals.
Conclusion
Boxy or square rails are a popular design element on many shortboards and high-performance surfboards. The angular shape makes the board feel fast, responsive, and loose. The sharp corners increase grip while also allowing the board to easily release from the wave face. This creates lively, snappy boards optimized for radical maneuvers.
However, the crisp edges provide less margin for error. Surfers need good technique to control the sensitivity and precision of boxy rails. The rigid feel can seem unstable in mushy surf as well. While square rails have become common in modern surfboard design, rounded rails still have their place for certain conditions, Ability levels, and riding styles.
By understanding how box rails affect performance, you can choose a shape that best matches your surfing goals. A knowledgeable shaper can further dial in the details like the width and sharpness of the rail to provide the ideal blend of speed, grip, slide, and responsiveness.
