How To Choose A Surfboard - Your Rails and Deck

In this article in our series How To Choose a Surfboard for you as a progressing surfer, we look at the rails and deck of your surfboard


The rails of your board are pretty much overlooked in surfboard selection.

This may be partly because rails are seen as a direct extension of board thickness. If you have a thicker board you'll have a thicker rail. If you have a thin board you'll have a thinner rail.

It may also be that stock boards, as opposed to custom boards, rarely if ever come with rail options. Big brands rely on moving mass produced products that have wide generic appeal at the sacrifice of performance.

Rail and deck characteristics can be discussed independently to a point, however the deck naturally flows into your rails so there is a directl relationship.

Let's see how these overlooked characteristics of rail and deck can greatly enhance your surfing performance.

Stock Board vs Your Board


There's no comparison between a stock board and your custom board. In a custom board a large number of details are matched to your personal characteristics, and most importantly how you surf now and how you want to progress

With stock boards there's a big focus on surfboard volume as it's an easy to grasp number that allows boards to be differentiated.

However volume is delivered as a just number and you get no indication of where the volume is distributed.

For example a board with volume under your chest will provide flotation. However a board with the same volume but distributed in a wide thick tail instead of under your chest, won't aid flotation.

If you're asked what volume you ride you'll likely have an idea.

Do you know what rails you like? What rail works best for you?

What about your deck?

Decks and rails receive little attention. However the biggest determiner of volume, apart from width, is the thickness of your deck carried across to your rails.

Volume, and your deck and more importantly rails need to be matched to your personal characteristics, surfing style, and wave conditions.

Flat & Rolled Decks


A flat deck above and a rolled deck below. The flat deck is considered better as your feet are more stable in their placement. It's easier to leverage heel and toe surfing to get your board on rail

Let's look at your deck first as we're only going to look at one aspect of it, the thickness transition from the middle to the rails. Other aspects like S and concave decks will be discussed in another article.

Your deck thickness can be either flat or rolled. This means if you put a ruler across your deck, across the width of your board, it will either sit flat or rock from side to side.

It is generally considered that flatter decks are better than rolled decks. A flat deck can still have a slight roll to it but doesn't slope dramatically away from the center to the sides.

When we talk about a flat deck, we'll be referencing a deck that's flat or has only a slight roll.

Rail Surfing


This image illustrates how a flatter deck facilitates rail surfing. On the left the board is on rail, the back foot is on its toes leveraging the rail into the wave face. On the right the board is flat on the wave face. The foot can't get on its toes as easily with the deck roll limiting leverage

With a flat deck you are more easily able to lean your board on its rail and into rail turns. This is because when flat on your feet you can easily lean onto your toes when going forehand, and easily lean back onto your heel going backhand. 

If your deck is already sloped it's much harder to get this leverage.

Getting your board on rail is the key to doing big manoeuvers.

A rolled deck also doesn't give you the consistent control. Your position on the board is twitchy as you're standing on the top of a curve. There's a tendency for your foot to shift to one side or the other and not easily return to the neutral center position.

So why would boards have a rolled deck?

It's an easy way to make boards without knowing the weight of the surfer, and so to cater for a wider market.

If you want to progress it's important to work with a Shaper who will take your weight and what your board is designed for, weak or powerful, clean or messy conditions, and put together a design that gives you a deck and rail shape to match, with the focus on enabling more rail surfing.

The Shaper can achieve this in many ways. For example your board can be thinner with a flat deck running all the way to the rails. Or your board width can be increased instead of having to add thickness into your board center creating the deck roll.

If things just aren't working on your board, if your board feels flat on the water and not wanting to go on rail, check the roll of your deck.

Rail Shapes


Thick versus thin rails are pretty much self evident. Both images show a board with same deck thickness however rail thicknesses, and shapes, vary greatly. This difference in rail shape will affect the way your board responds in different wave conditions

Rails are all relative.

What is a thin rail to you may be a thick rail to a smaller surfer like a Grom. So rails, and the descriptions here, aren't absolute. It's also another reason why you need your own rails.

However on the smallest Grom board rail height under the chest wouldn't drop below 1 inch. For a heavy surfer rail height wouldn't go beyond 3 inches for a performance board.

Bigger rails do exist on guns, paddleboards and SUPs.

Thick or Thin

The terms thick and thin for rails are self explanatory. There are additional descriptors that go with them that need some explanation.

Boxy, Full, Standard or Low


A full boxy rail top. A thin low rail below. These two rails surf very differently

A thick rail may also be described as boxy. This means it is full with almost a rounded square at the top and bottom.

A rail isn't normally described as standard, however a standard rail is not too thick, or boxy. It makes a reverse D shape.

A low rail means the rail isn't full at the top, it slopes down towards the bottom edge.

Soft or Hard


A hard rail top. A soft rail bottom

A hard rail means that the bottom of the rail has an edge. It may be a rounded edge or a sharp angular edge.

Soft means that the bottom of the rail is rounded. It may be completely rounded like an oval.

Where's The Rail


The slice at the top shows the rail under your chest. The slice below shows the rail at the tail. The tail rail is boxy and hard providing a mix of buoyancy and bite allowing a lot of drive to be applied without the board sinking into the wave

Rails around your chest area are normally full and softer meaning they have a slight or more rounded edge at the bottom.

Rails around your tail can be full or thin, and are normally hard, meaning they finish with a sharp edge.

What Do These Different Rail Shapes Do?

The softer rail under your chest is said to catch less in the wave.

So when you push into a turn and there's a bump or lump on the wave, or you overbalance, the soft rail is meant to not catch and allow a smooth continuation of your surfing flow.

With this kind of smoothness and not catching, direction change turns are easier. For example going into and out of hard bottom turns and cutbacks.

The hard rail is meant to give you more drive so that pushing into a turn you'll go farther, faster. The trade off is that you are said to catch. When doing a direction change turn like a cutback your board can catch more easily and bog.

However the context of this feedback, is all relative.

If you've been used to hard rails then you can sense when the rail is about to catch and compensate. Also with a hard rail you can do shorter arc turns if it's lumpy and bumpy so your rail isn't going through long arc turns where it's likely to catch.

For performance surfing you should try a hard rail. Softer rails offer a less dynamic option. Sure you can push hard on a softer rail, but the response is always going to be softer.

Surfing Style


These two images demonstrate rail usage. On the left Wilko has his front foot on the front rail. With his weight across both feet he's in the process of burying the rail in the wave. As his board comes around it will be a full rail gouge, a fuller boxy rail giving push-back so his board doesn't sink into the wave and gives a boost into his next manoeuver. Filipe on the right has his weight over his back foot where all the carving work is taking place. His front foot is in the middle of the board and his front rail is holding his line. Here a thinner front rail will be finer, so as to provide bite, and be easier to be whipped around in the change of direction

To determine whether your rail should be thick or thin, if you're a heavier surfer you'll need a thicker rail, and thinner if you're lighter.

However you can mix it up a little. You can see the difference in rails in the way the Pros ride waves. Surfers who have their weight spread across the board, burying a lot of rail in each turn, tend to have thicker and fuller rails.

This is because they don't want the board to sink into the wave, thicker rails providing buoyancy and push-back so they don't bog.

Surfers who ride from the tail may have a thicker tail block with finer rails up front. Being directed from the tail the front rail won't need too much weight or too much force to get the board to go where the surfer wants so can be finer and responsive.

Of course lots of other board attributes, especially rocker come into play, however this provides some idea of how rails work for different surfers.

Wave Conditions


This wave isn't that sloppy but you can see the lumps and bumps on the face. A thicker rail will help you not catch. Your personal choice will determine if you want the rail softer or harder, do you want to drive hard in short arc turns or still draw out longer softer turns

Wave conditions also need to be considered.

Interestingly Kelly Slater came out with a new board model with fine rails. Likely a direct result of surfing at the Surf Ranch, where the waves are clean, fast and not heavy. The new model's finer rails match the wave allowing faster more responsive surfing.

There's little to no paddling at the Surf Ranch, the waves aren't powerful, so the board doesn't have to have much volume or thicker rails either for float or big driving bottom turns.


Though slightly time exposed you can see the smoothness of this wave. A finer rail here will allow more responsive surfing, perhaps fitting more moves in or putting your board into normally inaccessible places as you'll have finer control. The alternative would be to use a fuller hard rail that could be planted for fewer more powerful moves

In comparison, for Hawaiian waves the board rails are thick and full. This is to cope with paddling, wave chop and bump, and with the wave power. Dropping into Hawaiian power you need to crank a bottom turn and you need a rail that can take your power and weight powering down on it, and not just sink into the wave.

Your Rails

Surfing locally, whether you're a light or heavy surfer, if you want your surfing to progress you need to try a thicker, harder rail.

Remember this thickness is all relative. So if you're a lightweight surfer you may already have a board with the right thickness rail. However if you're a heavier surfer chances are your rails are undersized as most stock boards are made for the generic market of smaller surfers.

A thicker harder rail will allow you to put your weight over it, and powerfully drive into your turns without your rail sinking into the wave.

Being able to do a good bottom turn will setup the rest of your wave. Good reentries, top turns and cutbacks will follow. Your surfing will change from being flat and soft, or skatie, to dynamic, powerful, rail to rail, and high performance.

For smaller waves you can try a slightly thinner or a lot thinner rail. You may still want to go top to bottom in the small stuff, but there may not be enough power in the wave. In which case a finer rail will give you more control and responsive surfing to position the board in the critical sections.

For bigger waves, a thinner rail can also work, as you tend to surf farther back on a longer board. Having a front rail that's too thick won't be responsive and will make your board feel bulky.

Your Quiver


At SURFit we talk about having a quiver. This may be a transition quiver, a series of boards you work through. Rails are definitely one board characteristic you need to work through and test.

You can also have a quiver of your best go-to boards with your best rockers, with the rails refined for the different wave conditions you surf. For example two identical boards one with a fuller rail for sloppier conditions, another with a finer rail for clean surf.

Tailoring rails and board design to your personal characteristics to progress your performance is what SURFit is all about.


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