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Understanding Stand Up Paddle Board Shapes and Styles

With many hundreds (indeed probably thousands) of stand-up paddleboard brands and designs out there to choose from, how on earth can you possibly work out what is right for you? writer Bill Dawes guides you through the maze…

While the SUP board market does indeed appear pretty bewildering at first, the good news is that it’s actually quite easy to know how a board will perform, and which type of board(s) you should be considering for your own use, once you understand how to interpret the board dimensions and the plan shape,

Sup Range 2020
Fanatic riders showing off a few of the different models in their 2020 range, which clearly shows the incredible variety of widths, lengths and plan shapes on offer .

Of the various dimensions that typically get listed in a board’s description, the two most important ones are length and width. Once you know how to interpret these two numbers you can instantly see what a board does and what weight/ability of rider it is for.

Understanding Board Length

The length of a SUP board determines what it does. Shorter boards are more maneuverable, while longer boards have more straight-line speed and glide. It really is as simple as that. There is nothing else you can automatically infer from the length measurement – in particular, it most certainly does NOT determine stability (ie you cannot assume that a longer board is automatically more stable), or weight-carrying ability.

So we can very easily group boards by length, as shown here.

Understanding Stand Up Paddle Board Shapes and Styles

Any SUP much less than 10’ long is primarily about maneuvering. It wants to turn. You can spin these shorter boards through 90 degrees with a single paddle stroke. Almost every board this size is designed for SUP surfing. They’re not good for much else as they are slow and frustrating to paddle in a straight line, because they always want to turn.

At the other end of the scale, anything much longer than 12’ is really all about straight line paddling; speed, and directional stability. So, not surprisingly, this is where we find the boards designed for racing and long-distance cruising.

Everything in between, ie from 10’ to 12’ or thereabouts, is essentially an all-rounder; still short enough to be relatively easy to turn, but with enough straight-line performance to be perfectly OK to paddle across the lake, up the harbor, or whatever.

So already, just a few paragraphs in, we’ve established a whole lot more clarity on the picture. If you’re not after a specialist wave board or race/touring board, then you can pretty much ignore everything shorter than 10’ or longer than 12’.

Now let’s look at the width.

Understanding Board Width

The maximum width of the board determines who the board is for. The width of a SUP board defines its stability, and weight-carrying ability. If you have two boards of essentially the same plan shape, the wider one will always be more stable and able to carry more weight. An inch or two difference in width can make an astonishingly large difference in stability. This is why the entire spectrum of all-rounder SUPs tend to span just a few inches in width; maybe 29” to 36”, with the vast majority being in the 31-34” bracket. It might not seem like a big difference, but a 34” wide board can probably handle almost twice as heavy a rider as the 31” board!

This is why many brands make their most popular shapes in a variety of widths, so as to cater for different weights of rider.

Red Paddle Co.
The Red Paddle Co Ride 10’8 is essentially the same board as the 10’6, but 2” wider. Likewise the Sport 11’3 is essentially the same as the Sport 11’0, just 2” wider. In each case the wider board can easily support 15-30kg more rider weight.

So if you’re looking for maximum stability and/or weight-carrying ability, then look at the wider designs. If you’re light, go narrower.

As your technical proficiency and paddling skills improve, you can move towards narrower boards, which are faster, due to less drag. They are also easier to paddle properly, as you can maintain a more vertical paddle shaft on a narrower board. This is why race boards inhabit very different realms of the width spectrum; the most radical now coming in at less than 20” wide! But that’s an extremely specialist machine. Your typical club racer is more likely to be on something around 23-25” wide – and will still find that technically challenging in any sort of bumpy conditions.

So the board’s length tells us what it does, and the width tells us who it is for. The third important parameter is plan shape. This tells us about the feel of the board, and where it sits within its general length grouping.

Understanding Plan Shape

You don’t need a highly trained eye to spot that some boards have more pointed noses than others, and some have narrow tails while others have wider, ‘square’ tails. These differences affect stability and glide and thus play a major part in determining the feel of the board.

Nose Shapes

Boards with rounded noses are often referred to as having a ‘mal’ plan shape, due to the resemblance to ‘malibu’ surfboards; the classic surfing longboard with a rounded nose and tail. While the rounded nose planshape does indeed have some advantages when surfing in small waves, the main reason why the majority of first-time/all-round boards have rounded noses is simply that the shape means the board can remain nice and wide much further forward, which greatly increases the stability.

Nose Shape
The round nose ‘mal’ plan shape (left), compared to the pointed nose (right)

However, it also means that there is a whole lot of nose up front which is far less beneficial when you’re paddling in chop or swell.

Paddleboards generally sit on the water rather than in it, particularly inflatable paddleboards as they have so much buoyancy. Very little of the board is underwater. So when you’re paddling, the board is primarily riding over the water rather than through it. However, the bow (front area) of the board is still having to push through the water, as is evidenced by the wake that is formed. The wider and blunter the nose, the more water you’re having to push through, and the more chop and well you’re having to deal with, the more it becomes a drag – quite literally!

This is why boards designed for touring and racing have a much more pointed nose – it makes a huge difference in terms of speed, glide, and drag. Narrowing the nose does reduce the overall stability a bit but creates a much faster and more directional board that will cope with chop, swell, and general ocean conditions much easier.

Tail Shapes

The ‘Mal’ style board has a rounded tail, which works well in an all-round capacity. It surfs nicely and is comfortable for general straight line paddling.

A square tail slightly decreases speed and comfort for surfing, but greatly increases the stability and weight-carrying capability. Consequently, manufacturers often use a square tail in conjunction with a narrower overall width, or a more pointed nose, because the square tail helps make up for the loss of stability caused by the reduced width or narrower nose.

Tail shape
Square tail (left) and round tail (right)

A square tail also tends to make a board easier for pivot turns, as it greatly increases the stability in the rear section. However, it definitely does reduce the maneuverability when you’re on a wave or hacking down a swell, which is why SUPs designed for surfing or downwinding have rounded tails or tails that come to a point (a ‘pintail’.).

Because a wide board with a wide nose and a wide tail is never going to score highly on maneuverability, some designers attempt to improve things in this department by making the tail more pointed. However, on a wide all-round board, this tends to fail because pulling in the tail just makes the board far less stable.

Favored Combos

So, putting all this together, it’s easy to understand why the vast majority of paddleboards are either ‘mal’ plan shape – wide, rounded nose and tail, (maximum stability), or the ‘bullet’ plan shape – pointed nose for greater speed and rougher water performance, with a square tail to offset the loss in stability from the pointed nose.

The classic mal plan shape, with rounded tail and nose

If you’re wanting a general-purpose board for the family, with no particular ambition to paddle any distance in rougher water, then the mal plan shape is great. If you’re wanting a board to go faster, further, and/or in rougher conditions, then the bullet plan shape is the one to go for.

The classic bullet plan shape, with square tail and pointed nose

Anything outside of these planshapes is either a specialist design for a specific purpose or a design that’s going to feel fairly different (probably worse) than other boards of similar overall length and width.

So the plan shape does have a big impact on the feel of a board. However, plan shape variations are secondary to length (and width) in determining the overall orientation of a board. Any board of 8’ long is almost certainly a wave board; the plan shape just defines what sort of wave board it is. A square tail 8’ board will perform differently to a narrow (pin) tail 8’ board, and the differences will be meaningful to the experienced surfer and determine which surf conditions the board works best in. Likewise, any board of 14’ length is probably a race board, but the tail and nose shape determine which conditions it will be best suited to racing in.

Underwater Shape

We are regularly asked what the real difference is between hard boards and inflatables. Other than the obvious differences in storage, transportation, durability, etc, the most significant difference is that essentially all inflatables have rounded rails and a dead flat bottom, whereas hard boards can (and do) have very complex rail shapes and underwater profiles, that vary continuously throughout the length of the board.

Flat bottom
Rounded bottom
Vee bottom
Single concave
Double concave

In a general-purpose recreational board this isn’t so significant, indeed the simple flat bottom of an inflatable is a very efficient approach. But when it comes to any environment where higher levels of performance are required, such as surfing, control in rougher conditions, or maximum speed, then the more sophisticated rail and underwater profiles of hard boards do tend to win out. (Particularly in surfing, where you need those hard thin rails in the rear section to bite into the wave. Inflatables, with their thick rounded sides, will never be able to compete in this department).

Understanding Stand Up Paddle Board Shapes and Styles
This Starboard hard board has a clearly visible central vee line with a concave either side, and then carefully shaped rails that thin out towards the tail.

So what of the so-called ‘displacement hulls’ that some inflatable brands now offer, and how do they compare to hard boards? The idea is that the ‘vee’ in the underside of the nose area cuts through the water more. However, it’s hard to tell whether it makes a much noticeable difference in terms of speed, because we haven’t yet had the opportunity to test a displacement hull board to another board of identical shape in all other respects but without the displacement.

Understanding Stand Up Paddle Board Shapes and Styles

It does seem to smooth the ride a bit for sure – paddling in light chop, you also notice less of the slap-slap-slap as you’re going through rather than over the bumps. But as it gets rougher, you also definitely notice the decrease in stability, because a rounded hull will always be more tippy than a flat hull. So it’s a bit of a conundrum and the jury is definitely still out on this. Ultimately, if you’re wanting a board for open ocean work in a variety of sea states, then a good hardboard will nearly always cope better with these conditions. They go through the bumps better, in a nutshell. Inflatables always tend to try and go over them, rather than through, and because you’re 5-6” up above the water surface on an inflatable, you’re much more subject to balance issues also.

So what of the other numbers you see on board stats; volume, thickness and max weight?

Understanding Volume

Don’t worry, you actually don’t need to! Volume only really matters with small boards or extremely heavy loads. As a simple rule, a board needs 1L to float every 1Kg of weight it has to carry (including its own weight). If you’re a pounds and ounces person then apologies, but this is one area where it’s just so much easier to do it in metric! So if the rider is say 90kg (200lbs) and the board is 10kg, the board needs 90+10 = 100L of volume in order to float. But actually, that would be a pretty tiny board. Pretty much every all-round iSUP is at least 200L in volume, most are considerably more. So in other words, they have masses of excess volume! There’s a lot of stuff online about how to calculate how much volume you need, but it’s largely nonsense or simply irrelevant. Choose the right length, width, and planshape for your requirements, and the volume will almost certainly be fine.

But hang on, you may well say, surely the more volume a board has, the more stable it is going to be, which is a good thing? Yet that’s exactly the problem with volume, it doesn’t actually have any relation to stability. Consider these three (lateral) cross sections.

Understanding Stand Up Paddle Board Shapes and Styles

Board A looks like your typical inflatable. Now if we double the volume by making it twice as thick, it will actually just become more corky, leaving you higher off the water. It won’t actually increase the stability at all. While if we double the volume by making the underside really rounded, it’ll in fact be way less stable, like standing on a log. The volume figure really doesn’t give us much useful information on its own.

Understanding Thickness

This is actually more of a construction thing than a parameter to determine board performance. Other than some yoga boards and river SUP boards which are deliberately made thick in order to keep the rider further off the water, thickness is not in itself a beneficial thing in board design, as the high sides mean less grip and more windage, the ride feels more corky, and obviously, a thicker inflatable is going to take longer to inflate than a thinner one. So in an ideal world, all boards would be relatively low thickness. However, the reality is that thicker inflatable boards feel more rigid, which is why most manufacturers build with 6” drop stitch – it’s just a simple way to achieve a stiff board. It is a much more technically demanding and expensive construction process to achieve the same rigidity with thinner boards, so only a few manufacturers tend to go there.

Understanding Maximum Weight

This is an utterly meaningless number. In most cases, it’s just some random extrapolation from the volume figure (which is also usually an estimation anyway!). And there is no definition or standard in how to measure this, so there is no way to compare the number from one brand to another. So don’t pay any attention to this – it has no validity whatsoever.

Understanding the market

So now you know how the essential parameters work, let’s apply them to the SUP market.

Board typelengthwidthplan shapenotes
All round 10’-12’30-34”Round nose, usually rounded tailThe classic all-purpose board that can be used in most situations.
Cruiser10’-12’32-36”Round nose, usually rounded, wide tail. Lots of width throughout the entire board for increased stabilityA more stable, but slightly slower version of the all around SUP. Great for casual cruises on the water.
Touring 11’-12’629-33”Pointed nose, often square tailMore streamlined to increase speed and directional stability.
Adventure/Touring11’-12’632-34”Pointed nose, often square tail, wider through the entire board than a traditional touring SUPMore stability and storage space for cargo, but still fairly efficient and fast on the water. Makes a great combo for solo fitness paddles and long paddle adventures that require packing a lot of gear
Race/Touring12’6-14’27-32”Pointed nose, usually square tailMuch more streamlined and narrow. Great for fitness paddling.
Race12’6-14’20-30”Pointed nose, usually square tailNarrowest is fastest on flat water but less stable, wider boards for ocean racing and heavier riders, pintails for downwinding
Surfing6’’-10’24-32”Wide variety! Pointed noses, rounded noses, and also square noses on the ‘nut’ style surfboards that look like big wakeboards. Tails normally fairly narrow, sometimes squared, sometimes pinCan vary from ‘longboard mal’ format for cruisy surfing to super short radical for high-performance slashy turns. But they are all boards with a specific purpose, and are not suited for general SUP use.
Yoga10’6-12’32-36”Round nose, usually rounded tailEssentially a wider, more stable cruiser with full length deck pad to give you space needed for yoga
Fishing11’-12’632-36”Round nose, usually rounded tailHave higher weight capacities and are best if they are wider and longer. Also should come with ample fishing mounts (action mounts, scotty mounts, tie-downs) for all your fishing gear.

If you have any questions about board design feel free to post them in the comments section below and we’ll do our best to answer them.

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