Custom Surfboards & Design Guide

 Southern California has some of the best most versatile and consistent waves in the world. I believe my environment has helped myself and other shapers create the best surfboards in the world. Designing high performance surfboards takes practice and southern California allows you to practice year round in a multiple variety of different kind’s of waves, from point breaks to hollow beach breaks, rights and lefts, to reefs of all kinds. I truly believe if I grew up in perfect powerful waves it would have hurt my shaping. In perfect waves that have lots of push with good shape you can make little mistakes in surfboard design and the board will still work to a certain extent and hinders pushing the shaper to be the best he can be. In mediocre waves you have to be “right on” in design because you are relying on design to make your own speed and performance and that is the best base you can have for your shaping. It’s much easier then to design for better waves which your boards will work that much better.

Choosing a Surfboard:

There are a lot of different factors in surfboard design and getting the right board for you sometimes can be confusing and complicated with all the technical aspects of design and performance. As a surfboard designer you want to keep the process as simple as possible for the rider. Any pro can ride any labels board and surf amazing, and he or she will tell you they don’t care how the board looks; all they care about is how it works. Here is some education to enlighten you on what design options will make your board perform to fit your style and personal finesse.

The Beginner:

I know at this stage you want to walk into your local surf shop and throw down seven hundred dollars for a surfboard but you would just be wasting your money at this point. I would spend half the money on a used short board or long board (I only mostly make short boards) which ever style of surfing intrigues you. This will be just fine for you to learn on and get you feet wet because at this point you wouldn’t understand differences between designs. If you are not sure of what board dimensions to start with I would take a look at the SHJ stock dimension for each style board. With all the stock boards and the dimensions, all the work and research is done for you of what works well for each size. I would start with a length at the minimum 4 inches taller than you are in height. This will keep the board a little more stable for you when you are trying to stand up and the paddle power you need to catch waves.

Some kids like to start on a really short thin board but in my opinion it makes their surfing choppier and less seamless when learning and progressing for the future. Again in my opinion a bigger board will teach you more flow because a bigger board is going to be a little harder to turn BUT, it will teach you to move around on the board find the sweet spots for turning and paddling and thinking ahead. Most important! You will learn to pump the board and surf very fast because that is what is needed to do a big quick slash of the lip of the wave, or long quick roundhouse cutback, or 6 foot air on a bigger board. It almost has the ankle weight affect and as you come down in board size your surfing just has that much more power and finesse. Every pro will tell if you can’t turn your board you aren’t going fast enough and SPEED is the key that will unlock numerous maneuvers and have you looking down the line thinking three moves ahead. It’s the difference between “average Joe surfer” and people pulling up to a break and saying “Who The Hell Is That???” Every top pro keeps the speed in the red and has seamless turns linking one turn to the next…and when done right it looks like they’re on a magic carpet. SHJ’s are built for speed and my theories and experience are translated to every board.

Intermediate-Expert-Pro Surfer:

At these stages it is a constant, never-ending battle to find that perfect “magic” board to fit your style and mindset of how you want your board to perform. Again, I like to try and keep it as simple as possible, but it can get complicated.

When designing performance surfboards, the best and simplest way to explain it to surfers is identifying which board design refinements really make the most difference towards improving their level of surfing. The main things to think about that will make a big difference when modifying your custom board are:

Length, Width, Board Outline, Rocker, Tail Shape, Bottom Contours, Fin Template, Fin Placement, Fin Angles, and Fin Set-up.

The Puzzle:

I like to think of a surfboard as a puzzle and the rider as what the puzzle has to fit, but first you have to make the right puzzle to fit that rider. (I’m trying to keep this simple so you don’t fall asleep).

Surfboard Length:

Shorter= Easier to maneuver but less stable, smaller sweet spot harder to catch waves less float.


Longer=More stable (bigger sweet spot) in bigger waves, easier to keep speed in mushy waves, easier to catch waves, harder to turn really quick or sudden maneuvers.

Surfboard Width:

Wider= the board the more glide (or speed) it will have to make sections of the wave, more stable, a little more forgiving sweet spot, pumping on the wave will be a little more drawn out. A little less responsive than a narrower board, less stable or lateral slide when waves are steep. Less of a hold in the face of the wave.


Narrower= Less glide from section to section of the wave but very responsive rail to rail when pumping. Good hold in the face of the wave when waves are steep and hollow. A little snappier feeling but harder to keep speed, less stability.

Surfboard Outline:

Outline= A more curvy outline in certain places of the board will make the board feel loose and responsive throughout your bottom turns and top turns. Usually smaller shorter boards have rounder outlines because they’re so short which make the outline have more curve from nose to tail. The outline of a surfboard is another form of rocker on the board. When you lay the board on the rail such as doing a bottom turn, the curve from the middle of the board to the tail dictates how the board is going to react. Again more curve means more of a tipping point to rotate your turns, less curve or straight means no tipping point to rotate the board and much harder to do very tight high performance quick arching turns.

Surfboard Rocker:

Rocker= Board rocker or the bend of the bottom of the board can be very tricky. More bend of the rocker makes the board feel very loose and less rocker or straighter bend of the bottom gives you more speed or drive from section to section of the wave. More rocker equals less of the board is actually in the water when bottom turning which make it very easy (loose feeling) to rotate (small tipping point) the board for quick snaps off the top or lip of the waves. The problem a lot surfers run into is; everyone would love to do big snaps off the lip and quick arcing high performance slashes on the face of the wave, but it’s very difficult. With a very loose high rocker board you have to be a very well rounded athlete to always keep your board in the “Perfect” sweet spot of the wave and calculate every turn with precision to keep speed.

This is why some people make the mistake of getting a board with the same dimensions as their favorite pro and find out very quickly it’s tough to surf like their favorite pro. The surfboard is there to enhance the ability of the surfer and great surfers can surf well on any board. When you find that certain refined design that fits a certain surfer perfectly, it can be a magical thing of beauty. Just like a motor sport athlete that finds the perfect setup to give him (or her) the confidence to push the boundaries of his or her abilities that make them finally break through to the next level of their sport.

Surfboard Tail Shape & Design:

There are many different tail shapes and each one makes the board turn a little or a lot different. Before I talk about tail shape I want to just touch on “tail width” because it’s very important. This is a preference and everyone is different. In my opinion surfers don’t pay enough attention to the width of the tail. There is a sweet spot everyone has for their back foot when bottom turning, pumping and doing snaps or cutbacks. If you have a size 10 (example) foot and you put your foot on that “sweet spot” we are talking about and it’s hanging off the side of your board this is not a good thing. When you are pushing hard on the tail (such as doing a bottom turn) and the tail of the board cannot sustain its buoyancy (which will probably happen if your foot is hanging off, which means the tail is not wide enough).The tail then will lose its plane or glide throughout the turn and lose speed or drive because its pushing water instead of planing on top of the water and gaining speed to hit the lip. You’ve probably seen numerous surfers try to do a big bottom turn to hit the lip and their board loses speed and they get hung up at the top of the wave (surfer error is also a factor).


On the other side of the spectrum the pro surfer might like the tail to sink a bit and dig into the face of a steep faced wave to do a very quick half roundhouse slashing turn (different waves need different set ups in design). Whereas a wider thicker tail would want to stay buoyant and almost want to bounce off the face of the wave and would be much harder to dig in a quick turn and take much more strength or force. We are again not all pros and the pro is surfing two to three times faster than you and is not worried about sacrificing some speed for performance. Just as a race car driver would want to sacrifice some speed in the straight away with more down force on the car to go faster through the turns. A lesser of a race car driver wouldn’t need to do such a thing because he is already taking the turn to slower for the down force on the car to make the same difference, again the car has to fit the ability of the driver just as a surfboard should fit the ability of the surfer.


Square tail: The square tail is the most common tail shape. A square tails shape keeps the board a little more stable or less tippy rail to rail than let’s say a rounded pin tail. Picture yourself laying your square tail board upside down (top of the board faced down) on a flat surface and try to rock it from rail to rail. Obviously the wider square tail is going to get in the way of the rocking motion and keep the board a little more stable than if you try to rock a rounded pin tail with two points at both ends which almost wants to spin from the two points (nose and tail). With this concept when you are putting pressure on the square tail there is more push back when let’s say bottom turning which give you a little more drive or boost through the beginning of your board pumping or bottom turn. Wider square tails work really well in sloped or mellow mushy surf and are usually made on a shorter board then your standard short board to make up for the really wide tail. Now you know why Dane Reynolds rode this same style board for the Lowers event.

Trying to use this style board in steep or hollow surf can be tough because the really wide tail will not want to dig into the face because the large surface area of the tail and could slide and lose stability. This is where the “Swallow Tail” or “Fish Tail” comes into play. With a swallow tail you can keep the tail wide but the two sharp points of the swallow tail will still dig into the face of the wave for stability (less sliding) in steeper waves. You will lose a little drive compared to the square tail design because the two points of the swallow are causing more drag while digging in the face of the wave or bottom turning.


Rounded Pin Tail: The rounded pin tail is a common design in very fast open faced waves (or point breaks). The reason for this is; with these types of wave you are traveling at a high rate of speed which equals all of your turns will be longgg and drawn out. The rounded pin tail has a continuous curve throughout the whole tail which keeps your turns very smooth, just like the smooth curve through the whole tail. A little tougher to surf small tight beach break waves with this tail because it’s difficult to get a very tight radius turn beach breaks require. You might be able to get away with this tail in beach break waves if you have a really short board (which then has a very round or curvy outline to keep the board loose and turns tight… now you’re understanding a little more of the right “PUZZLE” pieces you need for certain designs). The pin tail is mostly used for very hollow waves because the “pin” tail is a very narrow, thin, sharp tail which will almost stick in the face of the wave and work with the fins to give the board a nice hold and trim throughout the barrel. Not good for high performance directional changes. You will notice this design ridden in waves where the rider is just going one direction (barrel or big straight drop on large waves).

Surfboard Bottom Contour:

To keep this subject simple, different bottom contours are designed to grab and or release water. Let’s say a concave board is going to “grab” water when turning compared to a flat bottom board will allow the water to slide right off the rail. When grabbing the water you have another source to push off of when pumping to gain more drive or speed. Just like if you were ice skating and had a flat edge which would have less bite and less grip to push off of to gain more speed, rather than a very sharp edge blade that will dig into the ice and allow you to put all your weight into to thrust forward (pumping the board) to gain maximum speed. Less concave allows the board to slide more and make direction changes and a little more forgiving. If you are surfing a waves where you are constantly trying to make sections of the wave and struggling for speed you might want a little more concave. If you are surfing a better shaped wave and are not too worried about the extra grip of the board you might want a little less. This really comes down to the board rider and the feeling you want under your feet. There are some other factors of allowing more air under the board with curtain concaves but average person doesn’t need to worry about that.

Surfboard Fins:

When I started making boards at the age of sixteen a never realized how important this subject is, and in my opinion can make or break a board design. If you want to know how important fin’s and fin design is; take the fins off your board and try to go surf…good luck. Fin template and placement on your board can make your surfboard very loose and responsive to as stiff as a board and barely able to turn. This is like a race car driver adjusting and refining the stiffness of the steering to give him the confidence to put the car anywhere he wants, just like a surfer to put his board where ever he wants. The bigger the fins the more area to push off against water (just like concave we talked about) to gain maximum speed or drive.

Small fins less surface area keeps the board looser for up and down high performance surfing. You have to find that happy median to fit the board design and to then fit surfer preference and wave style. This is why you will see Kelly Slater have different fin set ups in different heats…maybe the waves got mushier or steeper with a tide change and he needed a little more drive or looser feeling board. Not enough drive in mushy waves and all your maneuvers will be off…speed and maneuverability is everything.

Fin placement can make a big difference as well. A more drawn out or spaced apart cluster will make the board stiffer feeling when rotating a bottom turn to top turn then a tighter bundle cluster. Just think if you lay your board in a pool and you try to spin the board, if the fin setup is wide apart from trailer fin to side fins, it’s going to get in the way of spinning that board unlike having a tighter cluster or less space apart or trailer fin closer to side fins. The same principles apply when you are doing a bottom turn and spinning or rotating the board to hit the lip. The amount of fins can also have the same affects in stability, drive, stiffness, looseness, rotation. The same goes for fin template or shape as well.

Fin Foil:

Fin foil is an extension of customization of the fin template. The foil of the fin is where the inner face shape of the fin meets the outer face of the fin. You will notice most side fins have a flat sharp edge on the inside face of the fin and the outside face of the fin is rounded. A sharper inside (inside is the side you are pushing off of when pumping) flat edge of the fin holds and grabs onto water when turning while water pressure hits parts of the outside foil of the fin to want to turn the fin or create lift. A more rounded edge releases water more when you turn and has more give or controlled slide to rotate your turns instead of the board grabbing and driving forward. You’ll notice the back trailer fin is rounded on both sides to create a point because the back fin has to have some give or slide equally both ways and equal amount of water pressure to keep the board feeling balanced turning left or right.

The best and simplest way to understand this is to grab a cup or glass with a really blunt or sharper edge on the lip where you drink out of. Then find another glass with a really round soft edge. When you poor water out of the sharp blunt edge cup (in the sink), the water comes out very streamline and doesn’t want to run onto the side of the glass. When you try this with a round soft edge cup the water releases and slides over the soft edge and runs all over the side of the cup making a mess. This is the same principle as the grab and release of fin foils. You can customize your turns to be smooth and/or a controlled slide, or have a lot of bite for a quick, less forgiving response.

Fin Flex:

Fin flex is also a factor; more flex gives you more spring or boost out of your turns and a stiffer fin gives you more response and straight-forward drive.

Most pros will use a very stiff fin for performance and drive because they already surf so fast and turn so hard they don’t really need the extra boost throughout the turn. Example: A pro golfer will use a very stiff, less forgiving shaft club for performance and drive, while a weaker or less of a golfer, needs more flex for boost and more forgiving club. I hope that helped a little.

Finally- Completing the Puzzle:


Just because you make a surfboard with a thin nose, tail, and fins, doesn’t mean you are a surfboard shaper. If you don’t put these pieces together in the right way or don’t understand how and why these pieces do what they are meant to in the water regarding design, you will never progress as a surfboard designer. As you can see, this takes years of surfing and testing every piece of these puzzles pieces in hundreds of different variations to truly figure out what works well. Also, every condition (or wave) is different, as is the surfer, which starts a whole new set of testing. You have to know which combination to put together to make each different surfer shine.

For example: If I see a board at a surf shop made with an outline with a lot of curve and a lot of rocker in certain places of the board, I better see a fin set up (template, angle, placement) to calm this board down a bit. If not, this board is going to be out of control for the average/intermediate surfer. Again, just because you make a surfboard “look” like a surfboard; it has nothing to do with you knowing how to design boards. I think the most common mistake I see regarding new board makers (and others) is the “foil” and volume areas of the board. This can be very difficult to make the board float equally (or balanced) from nose to tail, and if this is not done correctly, it will almost certainly ruin the performance of the board.

I hope that helped explain a little bit about what goes into making a surfboard work. If you need help finding the magic set-up, first find yourself as a surfer (every pro has a certain style and maneuvers), then start experimenting with the “puzzle pieces”. Lastly, ask your shaper (I know of one!) to make your board perform the way you need it to so it enhances your surfing to the best of your abilities.

If you need help, just ask. We are here to make you a better surfer.

(SHJ Surfboard Models)

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Practice makes… more practice.

Shane “SHJ”

SHJ Custom  Surfboards Huntington Beach CA

SHJ Custom Surfboards Newport Beach CA





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