The Theory Of Surfboards

Materials

BLANKS
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A blank is the core of your traditional surfboard. Clark Foam held the world at bay with its “close tolerance”, polyurethane blanks up until December of 2005. Close tolerance blanks refer to how near a blank is to a finished shape. Although there are other polyurethane blank manufacturers out there, alternative design has catapulted into the spotlight since Clark’s closure. There are expanded poly styrene (EPS) blanks—a material that resembles quite closely your average Styrofoam drinking cup—which must be blown in close tolerance molds and are being popularized by companies like Firewire.

Firewire use a layered process of glassing to create the “shell” around the EPS blank made up of molded PVC and fiberglass resin wraps. The result is a light and incredibly durable surfboard. Check out Firewire for more info.As of now, the majority of the surfing world is loyal to traditional, polyurethane blanks and alternative technology—though advancing rapidly in a great direction—remains just a pace behind in popularity

GLASSING
Fiberglass cloth along with resin (the hardener) is the shell on your traditional board or your Surftech. In both instances fiberglass is used along with as the structural strengthener of that shell. On a polyurethane shortboard, the accepted choice of cloth “weight” is a 4 and 6 ounce combo on the deck with a 4 ounce bottom. Longboards are heavier; usually with 4/6 ounce decks and 6 ounce bottoms. There are two widely used types of fiberglass for the traditional polyurethane surfboard. “E” cloth is the most commonly used of the two. “S” glass is stronger but more expensive. You can use a combination of the two if you choose, but this is a custom touch and you must request it.
FINS
Fins are the most highly argued, innovation friendly aspects of surfboard design. Just check out surffcs.com, lokboxfins.com, futuresfins.com or trueames.com for all you can handle on fin technology.What you should know, however, is that a fin is more or less the steering column of your surfboard. Pressure from your front and back feet cause rail changes that channel water through the fins, causing them to react, thus affecting the speed, control, drive and maneuverability of your surfboard.Increased rake (the amount of distance between the front base of the fin and its tip) adds drive, as there will be more water flowing and clinging around the fins but it also makes your board stiffer, as there is more surface tension in the water. Less rake means, of course, less drive but it enables the fin to “pop” out of the water. In the same way, the thickness of the tip of the fin correlates directly to control versus looseness. A wider, rounder fin tip will produce more drive and control whereas a thinner, pointier fin tip will require you to drive harder but will allow you to do those “fins out” turns you strive for. Just imagine the keel of a sailboat here: if it is longer and more tapered, the boat will be more stable but will take more sail to turn hard. If the keel is short and more straight-up-and-down the boat will be fidgety in the water but turn easily and fast. Remember, there are many more subtleties and features of surfboard fins that affect the way they perform, but it is important not to get lost in all the details and to just be familiar enough with your equipment to know how and why it functions the way it does.

 

Definitions and Term

Dimensions

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Surfboard dimensions follow the same formula of measurement as any other constructed thing: Length Width Thickness. You will find the dimensions of your surfboard on its stringer

Stringer

This is that strip of wood you see running down the middle of your surfboard. It provides strength and a center for “flex” in your board. New, alternative surfboards like Surftech, Salomon and Aviso do not have wooden stringers and rely, rather, on the strength and flex of the materials they’re built with.

Lenght

This is the distance from the nose to the tip of your surfboard, measured along the stringer. Length is one the most important factors for a beginner when they are considering the right board to help them evolve into a better surfer. Longer is better so long as it correlates with a wider template and thicker rails. Shorter is usually a realm best reserved for an intermediate to experienced surfer.

Nose

This area at the top of the board (measured at a point twelve inches down from the tip) is more important than most people think. A thinner nose is almost always associated with a higher-performance surfboard geared toward larger waves and is accentuated with greater rocker. A wider nose can be found on beginner and small wave boards as its greater surface area on the bottom captures and channels more water through the wide point and tail of the surfboard. More water usually means greater stability, speed and better planeing.

Widepoint

This simply refers to the widest point (rail-to-rail) of the surfboard. To find your surfboard’s widepoint, hold the board out in front of you with the tail on the ground and gently grip each rail near the nose. Then slide your hands down along the rails and watch for the apex of the curve of your board found just before your hands begin to slide inward down towards the tail area. Wide points vary and often “forward” wide points (pushed toward nose) aid front-footed surfing and “pulled-back” wide points (pushed toward tail) aid back-footed surfing. Generally, the wider the board is the more stable it is and the more suited it is for smaller surf. The narrower and vice versa.

 

Tails

Like the fins, tail design is a highly argued yet innovation friendly aspect of a surfboard. To name all of the tail shapes that have passed before us since surfboard shaping went full throttle more than forty years ago would be exhausting. There are a few, however, that have come and stayed and will always remain.

Swallowtail: Ankle-to-giant conditions. The wave size spectrum is so great here because there are two, very different types of swallowtails: “fish” and “baby” swallows. The fish is a highly effective and fun choice for small wave surfing. The wider the swallow, the straighter the outline of the board will be, thus there will be more drive which is important when the waves are weak and you must generate your own speed.

Baby swallowtails are tighter, much smaller and are very popular with big-wave surfers. Essentially, a baby swallow cuts some length from the surfboard and provides two points on which to turn from. This is crucial when the waves are big, therefore baby swallows have proven themselves time and time again at places like Todos, Mavericks and Waimea.

Squashtail: Knee-to-overhead conditions. The squash is the child of the square. The edges of the once sharp square tail are simply rounded a bit to create a “squashed” appearance. This tail results in a design that is more stable than the square yet still loose when it needs to be. The squash is by far the most popular and versatile tail today and is an excellent choice for beginners and experienced surfers alike.

Thumbtail: Waist-to-double overhead. This design was created out of the need for a shape that was a bit more stable and clean than a squash. Because there is no hard-edge, or “interruption” in the flow of the rail, water moves cleanly from nose to tail. The thumbtail is a board made with not just carving in mind, but also flair. This design is definitely a great alternative from the squash when you want a board that is extremely fun in surf with some juice.

Rounded Pintail: This design is for those bigger days when a pintail is too much and a square, squash or thumbtail may not be enough. You’ll find this tail on our Traveler, which is a board that handles in steep, concave waves yet is fully capable of quick-turning and tight arcs. Like the thumbtail and pintail, there is no interruption in the flow of the rail through the tail, thus enhancing control in the pocket.

Pintail: Double overhead + conditions. This is an elongated, sharper rounded pin. It is only effective when the waves are big. This is because it provides for a very narrow (rail-to-rail) tail that “locks” into steep, concave wave faces, resulting into a high level of control when speed is in an overabundance.

Battail: Waist-to-overhead conditions. This is a very modern design and can be found on our Quad (four-fin) model. Like a swallow, the battail creates a “double” tail design that essentially gives you two points to maneuver off of. The center point adds stability and a great pivot point for rail-to-rail surfing. This is a very fun design and everyone should give it a spin.

 

Thickness

Thickness is a very important feature that everyone—from beginner to experienced—needs to be aware of. It will determine in many ways how the other design features of your board will work. The thicker the board the more stable and buoyant it will be—obviously this is important for a beginner. But more technically, thickness can change in a surfboard’s template in countless different areas, all of which directly relate to stability and responsiveness.

 

Rails

Basically, there are two types of rails: 50/50 rails (which derive from older, pre-shortboard design styles and are found more on longboards) and “down-turned” rails, which can be found on almost all modern surfboards. A 50/50 rail is shaped the way it sounds, meaning the apex, or mid-point, of the curve is in the middle of the rail, creating an egg-like shape that sits high on the water’s surface. Because this type of rail lacks a sharp edge on the bottom, water can more freely flow out from the bottom of the board as you plane down the face of the wave. This buoyancy and a lack of edge make a board with rounder (50/50) rails much harder to maneuver. A “down-turned” rail is probably what you are used to seeing, as it is the popular choice on most any surfboard today. It begins, essentially, as a 50/50 rail from the nose then at about three-quarters down the rail develops a sharper lower edge to accommodate the flat bottom of the tail area. This sharp edge holds through into the tail and helps to capture the flow of water from the nose and keep it underneath the board so that it creates lift as it runs against the fins in a tighter manner. Down-turned rails are so popular because of the extra maneuverability they give a surfboard. They’re stable yet necessary for vertical, modern surfing.

 

Rocker

Describes the overall curve of the surfboard from nose to tail. On a modern surfboard, rocker can be broken down into two different sections: rail (which includes nose and tail curvature) and center (curvature of the middle of the board).

Increased nose rocker is usually attributed to boards shaped for bigger-wave surfing. More rocker in the nose allows for a shape that will not “pearl” or plunge into a large, steep wave face when you dropping in.

Increased tail rocker can be found in boards shaped for optimal maneuverability. A tail that bends off of the water’s surface provides more lift and sensitivity in the tail for driving through radical turns.

Generally speaking, on your standard surfboard, less overall center rocker means the board will glide and paddle better and be more suitable for beginners. More rocker will accommodate intermediate and experienced surfers looking to use every area of the board in order to generate speed and turning power.

 

FOIL

Foil is how areas of thickness correlate with other areas of thickness from nose to tail, deck to bottom and vice versa. Essentially, good foil is an even distribution of thickness as the nose fades into the wide-point and then into the tail. Imagine trying to turn a board to go down the line that has a brick attached to the nose or the tail—the “swing” will be off balance. Good foil translates into good flow as the board moves from points on the nose to the middle and to the tail throughout the duration of a ride.

Foil can also be used to describe some fin designs. Foil in the fin holds the same concept as it does on a surfboard. The thickness must be balanced throughout or the fin will not do what it is made to do—it will be too stiff or too flexy, or it won’t channel water smoothly.

 

CONCAVE

Concave, has undergone many mutations since shapers began experimenting with it in the ‘60’s. There are four basic types you should be familiar with:

Single: Chest-to-double overhead+ conditions. This is a single channel in the bottom of your board running from the nose through into the tail, resembling a faint “dug-out” appearance. Here the flow of water is not refracted and is collected from the nose into this channel and runs uninterrupted through the fins. Single concave is designed for fast, large waves where you can expect spending more time in the barrel than hitting the lip.

Double: Ankle-to-overhead conditions. Instead of having a channel dug out of the nose area, the bottom of your board stays relatively flat to about three-quarters of the way down then develops a “hump” that splits the water off into your two side fins. This is a great board for smaller waves because the flat front portion of the bottom of your board provides glide and speed-boosting planeing, then the double-concave gets your maneuvers going.

Triple: Ankle-to-double overhead conditions. This begins just like a single concave in the nose then develops that same “hump” within the single concave about three-quarters of the way down the bottom of your board and stays that way through the fins. This design takes the clean channeling principle of the single concave then adds a split to better push the water into your two side fins. This is an effective design for small-to-medium waves because as you drive down the line of a slower wave, the double concave assists you in getting the flow of water where it should be so that you can turn more easily.

Channels: Knee-to-overhead+ conditions. These are radical concave additions that have always been and still are experimental additions to design. Channels are always found in the back-quarter of the board through the fins and tail. They increase speed as the water flows through the many “gullies” that make up a channel bottom. They also provide for a different feel while engaged in rail-to-rail surfing.

Vee: Vee does not usually stand alone as a bottom feature, rather it can accompany all of the above concaves. To begin understanding vee, you must also be able to imagine double-concave. Vee is like a “hump” but it doesn’t “dip” into the curved funnels that are double-concave. In other words, double-concave looks like two half-pipes side-by-side (the middle being the stringer) while vee looks like two triangle-ramps side-by-side or, simply, an upside down “V”. In modern design, vee is usually designated to the tail area behind your rear, trailer fin. Vee helps break the chop in a wave face and adds that last separating push of water off the tail when executing turns. Vee is complicated and is not an important design feature for the beginning surfer to try and grasp completely.

 

FIN SET-UPS

Single: The single-fin is where it all began. It originated from the keels of sailboats. It provides a central stabilizer for your board. Because it is only one fin, the single-fin is always quite large resulting in a surfboard that has a lot of drive (due to the fact that resistance is reduced down to one fin instead of two, three, four or five). This is a fin design that works well in large surf because the depth and centrality of the fin makes for a “stiffer” board (not so snappy) but when it does swing into a turn it holds very well, even when the wave your on is bigger than your house.

Twin: The twin-fin came next. This is a fin design that lends to surfing that can be either squirrelly or “stuck” in a straight line unless you can keep the board smoothly transitioning from rail to rail. But unlike the modern thruster and other “more-than-two” designs that help you work the board from one rail to the next as you plane along a wave, the twin requires you to have enough talent and ability to perform such a task. When you’ve got a twin dialed in, however, you can really drive quickly down the line, whip through turns and bust loose.

Thruster, or tri-fin: The thruster is sometimes considered the best surfboard design innovation in the history of our sport. Invented and pioneered by Australian Simon Anderson in 1981, the thruster was first met with criticism until Anderson began winning pro contests on it. Ever watch a mid-seventies surf flick? The surfers sometimes look a little out of control on their twin-fins, right? Then you look at a mid-to-late eighties into modern surf flick and all of a sudden everyone got real smooth. That’s the beauty of a thruster—it took all of the best aspects of the twin then corrected it’s instability with a center, equally sized “trailer” fin and, bingo, the world had the most stable surfboards yet. Beginners should always start out on a thruster design.

Quad: The quad is an attempt at correcting the squirreliness of a twin but still maintaining that fast, whipping style. This design is becoming increasingly popular with big-wave riders because of the rail-strength in big bottom turns and the speed generated in the absence of the drag of a center fin.