NATURAL CURVES SURFBOARDS

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CURRENT DESIGN TOPICS

 
Quick links to various Design Topic Essays on this page
 
 
 
Acceleration & Foiled Profiles | Rockers & Profiles 1960 - 1990 | Rockers & Profiles 1990 - 2020 | Mid Length Designs | Flat Decks | Single & Double Concaves | Tuning & Detuning Rails | 2017 Rockers


 
ACCELERATION & FOILED PROFILES
 
 
 
From October 9, 2020 Updated February 6, 2021

Profiles & Foils

Profiles and foils serve many functions in surfboard design. Not the least of these is acceleration. The two elements of a design's profile and foil are the bottom rocker and the deck rocker. Together they form the design's profile and foil. A well designed profile is a foil. See
"foil" and "Brounelli Principle" below. Designing acceleration into a profile and foil would include a bottom rocker that fits naturally and comfortably in the critical parts of a wave with curves that tap into a wave's energy. A rocker like this offers or provides the design with acceleration, speed, maneuverability and control. The profile and foil of a design also includes the deck rocker. The relation of the deck rocker to the bottom rocker accounts for the distribution of volume in the profile and foil, the other primary factor in distribution of volume for the whole design is the board's surface area determined by the outline. A foiled profile distributes the volume in a manner that creates lift and reduces drag, ultimately providing acceleration and creating and maintaining speed.

Distribution of volume effects how and to what degree a surfer displaces water by weighting and unweighting the board's bottom, profile, and rails. This basic shortboard technique or style accelerates the surfboard and generates and maintains the speed required to perform the vast array of maneuvers common to contemporary surfing. Engaging, holding and releasing the bottom, profile, and rails in the face of a wave amplifies the lift and reduces the drag components of a foil moving through water. This technique is functional in all conditons. It may be performed across the whole spectrum of surf conditions and venues - critical, high quality, fun, or marginal.

How does a foiled profile contribute by design to these performance features: acceleration and generating and maintaining speed?

The distribution of foam and therefore volume in a profile creates the performance features of this element of design. As previously mentioned, a well designed profile is a foil that creates lift and energy and reduces drag by harnessing energy from a wave as it moves through water. This lift generated energy and reduced drag create the acceleration and speed that a surfboard offers a surfer. This occurs when water flows along the bottom of a board creating a force perpendicular to that flow generating lift that is substantially greater than the drag of the board in the water. The lift and energy generated by the foil is then transferred into the the acceleration, speed, and maneuvers performed while surfing. Tuning and controlling the lift to surfer and conditions with design features is an essential part of surfboard design.

In 2021 a foiled profile, functional in a variety of conditions, includes features developed and tuned over 50 plus years of evolution of performance shortboards.

Foil History - devolution and evolution of profiles and foils in shortboard designs

Late 1980s

Shortboards date to the second half of the 1960s. Contemporary Performance Shortboards date to the late 1980s and early 1990s. Prior to that era shortboards were generally high volume designs featuring moderate length, full rails and outlines, and convex bottom contours. The first generation of Contemporary Performance Shortboards are often refered to as "Glass Slippers." They were extremely low volume designs featuring a very narrow outline, a very thin profile and foil, significant banana like rocker with accelerating tail and nose rocker, and deep concave arrays. These low volume designs remained the prototypical shortboard for 10 to 15 years despite their many limitations.

1990 - 2000

These early performance shortboards, the "Glass Slippers," were relatively long and extremely narrow and thin compared to today's shortboard designs. Average dimensions were 6' 0" to 6' 2" long x 17 3/4" to 18" wide x 1 7/8" to 2" thick. The basic distribution of volume was thin in tail, thin at the wide point, and even thinner in the nose. Typically, these profiles were 1/8" to 1/4" thinner 12" from the nose than 12" from the tail, and 1/16" to 1/8" thinner 24" from the nose than 24" from the tail. These designs featured banana like rocker and deep concaves. The relatively thicker back half of the profile and foil was designed to support the surfer with lift from surface area, deep concave array, and moderately foiled profile from wide point to tail. The nose was designed thinner to eliminate the effect of nose volume on the board's performance.




1990 to 2000 Foiled Profile with original contemporary performance shortboard distribution of volume - extremely thin throughout - extreme entry and tail rocker - extremely low volume


The exciting performance features of these low volume designs overshadowed their lack of versatility both in various conditions and across the spectrum of surfer skill. This attraction to the potential for radical surfing was like a lead weight on surfboard design and surfing performance for nearly two decades.

2000 - 2010

Boards started to get a little shorter, wider, thicker, and featured more nuanced rockers. Concave bottom contours were also moderated and tuned to improve overall performance while maintaining the lift factor they bring to these deigns. Performance shortboards of this era were on average 5' 10" to 6' 0" long x 18 1/2" to 19 1/4" wide x 2 1/4" to 2 3/8" thick. One feature remained the same and that was the distribution of volume in the profile and foil. The profiles and foils were still 1/8" to 1/4" thinner 12" from the nose than 12" from the tail, and 1/16" to 1/8" thinner 24" from the nose than 24" from the tail.

These design changes initiated an era of expanded performance range for shortboard designs. Designs were notably more efficient and versatile than their Glass Slipper predecessors.




2000 to 2010 Foiled Profile with original distribution of volume - thicker at widepoint - moderateely thicker nose and tail - moderated entry and tail rocker


2010 - 2020

Surfboard design continued it's trend toward improved and more versatile function and performance. Twenty plus years of design, shaping, and surfing provided surfers and shapers with volumes of observations, feedback, and input to improve performance and versatility of contemporary shortboards compared to the 1990 Glass Slipper. Designs continued to improve performance and versatility across the whole spectrum of surf conditions. Efficient and practical design edits saw boards going marginally shorter,wider, and thicker compared to the previous 10 years. Common dimensions of this era are 5' 8" to 6' 0" long x 18 1/2" to 19 1/4" wide x 2 1/4" to 2 3/8" thick. One element of design that shifted notably is the distribution of volume in the profile and foil. As boards got shorter, more efficient and more versatile it was important to maintain volume or even add some volume to the core of the shape. Shapers started to hide foam in shapes corresponding to the area under a surfer's torso when paddling and stance when riding waves. Outlines also added hidden surface area in the same area with the same goal. The center of mass moved slightly forward with these volume and surface area adjustments. The other primary design elements, rails and bottom contours, maintained their features.




2000 to 2010 Foiled Profile with original distribution of volume - thicker at widepoint - moderately thicker nose and tail - moderated entry and tail rocker

2020 - 2021

The evolution of performance shortboards from 2010 to 2020 was truly a very practical and efficient era in surfboard design. 2020 and 2021 sees that trend continue. Performance shortboard designs added and shifted a bit more volume and surface area forward. Adding and shifting volume and surface area to this area of designs was new to the basic all around shortboard, but not new to all designs. Step ups, semi guns, and big wave guns successfully featured hidden volume, equal and sometimes greater thickness in the nose than in the tail, and outlines with the widepoint and surface area shifted forward. When applied to contemporary shortboards this forward shift in the distribution of volume and surface area creates a better more efficient foil thus generating more lift, reducing drag and consequently providing more acceleration and speed. Lift reduces drag, reduction in drag increases acceleration and speed.




2020 - 2021 Foiled Profile with volume shifted forward - moderate thickness throughout - thicker nose and thinner tail - moderate entry rocker and lower tail rocker - versatile and efficient design - generates and maintains speed - accelerates on demand

Matching Volume to Surfers with Custom Designs

Surfers vary in age, gender, size, skill, fitness, and technique or style. Matching volume to these variables is essential to maximizing the performance of a contemporary shortboard. Correct volume for one surfer may not be correct for another. The
Theory of Volume and the Theory of Displacement allow surfers and shapers to tune dimensions appropriately.

Link to Theory of Volume

Link to Theory of Displacement

What is a "foil?"

In physics and fluid mechanics, a foil is a solid object with a shape that when placed in a moving fluid at a suitable angle of attack the lift on the object, the force generated perpendicular to the fluid flow is substantially larger than the drag, a force parallel to the fluid flow.

A foiled profile of a surfboard is a shape that when under the power of a wave and being maneuvered on and through the water by a surfer transfers the generated lift and energy into forward acceleration. The greater the lift the greater the reduction in drag. Less drag yields greater acceleration and speed in a surfboard.

Brounelli's Principle Applied to a Surfboard Foil

Brounelli's principle states that increased speed of a fluid on a surface occurs simultaneously with a reduction of pressure on the same surface. The reduction of pressure results in a transfer of energy we feel as lift in a surfboard. The distribution of volume in a foiled surfboard profile benefits from this principle. When a mass of fluid water in surfboard design and performance is flowing horizontally from a region of high pressure to a region of low pressure there is more pressure behind than in front. This gives a net force on the shape the surfboard accelerating along the horizontal line. This explains how a surfboard foil will perform when the distribution of foam varies from thinner, to thicker, to thinner from nose to tail, providing lift that is transfered into acceleration, speed, and maneuverability.

Foil and Fluid Mechanics


Link to Wikipedia overview of foils and fluid mechanics



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ROCKERS & PROFILES 1960 - 1990
 
 
 
November 10, 2020
 
 
 
Rockers and profiles evolved at a rapid pace from the mid 60s to the mid 70s, the first 10 years of shortboard evolution and design. Rockers settled into a familiar pattern in the mid 70s and have continued to evolve with the same theme of entry, mid board, and tail rocker.

The images and dimensions below illustrate rockers and profiles from the first George Greenough inspired shortboards of the 1960s to the "Glass Slippers" of the 1990s, including the best shortboards of the 60s and 70s designed and shaped by Mike Diffenderfer and Dick Brewer.
 
 
The shortboard revolution started in 1966 - 67. George Greenough's kneeboard "Velo," a foam railed - hollowed out fiberglass bottom board inspired the first truly short surfboards. They featured very low entry rocker, nearly flat rocker from wide point to tail, and a foiled "S" deck. The distribution of foam in these designs was in fact a foil that offered great lift and acceleration. Surfing performance changed dramatically from trim and nose riding to accelerating high speed turns.
 
 
The 60s also featured the emergence of Mike Diffenderfer's early shortboard designs. Diff's curves introduced rockers and profiles that fit into the tight energy rich curves in the pocket of a wave. These designs featured moderate entry, flatter mid board, notable tail rocker, and a foiled "S" deck. This was a remarkable if not quantum leap in surfboard design. Fundamentally, Diff's rockers and profiles allowed a surfboard to tap into the powerful energy available in critical parts of a wave.
 
 
The 70s saw the emergence of Dick Brewer's "Mini Gun" as the prototypical surfboard design. RB's 70s rockers were similar to Diff's late 60s rockers featuring entry, mid board, and tail rocker. The Brewer Mini Gun fine tuned rocker from nose to tail. RB's designs, unlike Greenough and Diff's "S" decks, featured deck rocker that mimicked the bottom rocker. This profile would yield an even more efficient foil providing greater and more focused and functional lift, ultimately providing more acceleration, speed, and maneuverability to surfboard performance.
 
 
The 80s was a decade of relative stability in rocker and profile evolution. Surfboard design focused on refining the high volume shortboards of the 70s to create moderately shorter, thinner, narrower boards by the end of the 80s. Attention to detail and fine tuning existing elements of design were the primary factors in rocker and profile evolution during this era.
 
 
The "Momentum Generation's" surfing - Slater, Dorian, and Machado's generation of high performance shortboard surfing inspired a dramatic change in rockers and profiles. Their surfboards featured extreme rockers and very thin profiles. This was a quantum departure from the designs of the 70s and 80s. This "Glass Slipper" design was the foundation for the evolution of rocker and profile designs over the last 30 years.



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ROCKERS & PROFILES 1990 - 2020
 
 
 
October 9, 2020 Updated November 30, 2020
 
 
 
Rocker is an extremely significant element in the design of a surfboard. It's often said a great surfboard has "magic rocker." Well designed rocker is the foundation of a great shape. Bottom rocker and a well foiled profile are essential to great performance from a surfboard. Bottom rocker is generally the first design element a shaper puts into a surfboard. Once the bottom rocker is established the shaper will proceed to add the other elements of design to a shape.

Evolution is constant in surfboard design. Sometimes evolution in surfboard design is incremental and sometimes quantum. Rockers constantly evolve. Every shape and every surf session offers opportunity for observation and nuanced changes in design. Generally, these edits and tweaks are incremental in nature, but over time these incremental changes add up to vast improvements in design and performance.

The following images illustrate the evolution of rockers, profiles, and foils from 1990 to 2020. The first set of images and dimensions below illustrates evolution of rockers, profiles, and foils from 1990 - 2020. From 1990 - 2000 on one 10 year interval, from 2000 - 2014 on 2 year intervals, and from 2014 - 2020 on 1 year intervals. The length of interval between images can make changes more and less notable. Images on shorter intervals do not illustrate changes particularly well. Images on longer intervals better illustrate changes. The second set of images, compares 1990, 2000, 2010, and 2020 rockers, profiles. and foils. The images on 10 year intervals illustrate notable evolution and development of rockers, profiles. and foils. The third and final set of images is 1990 and 2020. The 30 year interval illustrates a quantum and dramatic evolution in rockers, profiles, and foils.
 
 
1990 "Glass Slipper" - solid entry rocker, Speed Box mid board, moderate tail rocker, extremely low volume profile.
 
 
2000 "Glass Slipper" - more entry rocker, longer Speed Box mid board, more tail rocker, extra low volume profile, slightly thicker nose.
 
 
2002 "Glass Slipper" - lower entry rocker, Speed Box mid board, more tail rocker, extra low volume profile, slightly thicker nose.
 
 
2004 "Glass Slipper" - lower entry rocker, Speed Box mid board, lower tail rocker, extra low volume profile, slightly thinner nose.
 
 
2006 "Glass Slipper" - slightly more entry rocker, Speed Box mid board, lower tail rocker, low volume profile, slightly thicker nose.
 
 
2008 "Relaxed Entry" - start of relaxed entry rocker designs, notoably lower entry rocker, Speed Box mid board, more tail rocker, low volume profile, slightly thicker nose and tail.
 
 
2010 "Relaxed Entry" - relaxed entry rocker, Speed Box mid board, notably less tail rocker, low volume profile, slightly thinner nose.
 
 
2012 "Relaxed Entry" - The Glass Slipper starts to have more volume - relaxed entry rocker, slightly more entry rocker, Speed Box mid board, notably more tail rocker, moderate volume profile, thicker nose and tail.
 
 
2014 "Relaxed Entry" - notably lower entry rocker, Speed Box mid board, significant tail rocker, moderate volume profile, thicker nose.
 
 
2015 "Relaxed Entry" - more entry rocker, Speed Box mid board, less tail rocker, moderate volume profile, thicker nose.
 
 
2016 "Relaxed Entry" - more entry rocker, Speed Box mid board, more tail rocker, moderate volume profile, thicker nose and tail.
 
 
2017 "Relaxed Entry" - same entry rocker, Speed Box mid board, more tail rocker, moderate volume profile, thicker nose and tail.
 
 
2018 "Relaxed Entry" - slightly lower entry rocker, Speed Box mid board, less tail rocker, moderate volume profile, thicker nose and thicker tail.
 
 
2019 - "Contemporary Performance Shortboard" rocker design - the Speed Box shifts forward - low entry rocker, Speed Box mid board moved forward, less tail rocker, moderate volume profile and foil, thicker nose and thicker tail.
 
 
2020 "Contemporary Performance Shortboard" rocker, profile, and foil - mid board Speed Box moves further forward - moderate entry rocker, Speed Box mid board shifted further forward, moderately low tail rocker, moderate volume, defined profile and foil, thicker nose and thinner tail.
 
 
 
The previous, first set of images and dimensions illustrates rocker, profile, and foil evolution from 1990 to 2020. After the 10 year interval from 1990 to 2000, images and dimensions are every 2 years from 2000 to 2014 and every year from 2014 to 2020. As mentioned previously, year to year design changes are not particularly notable. The following, second set of images compares 1990, 2000, 2010, and 2020 rockers and profiles, on 10 year intervals. The longer intervals notably illustrate evolution and development of these rockers, profiles, and foils.
 
 
1990 "Glass Slipper" - solid entry rocker, Speed Box mid board, moderate tail rocker, extremely low volume profile.
 
 
2000 "Glass Slipper" - more entry rocker, longer Speed Box mid board, more tail rocker, extra low volume profile, slightly thicker nose.
 
 
2010 "Relaxed Entry" - relaxed entry rocker, Speed Box mid board, notably less tail rocker, low volume profile, slightly thinner nose.
 
 
 
 
2020 "Contemporary Performance Shortboard" rocker, profile, and foil - mid board Speed Box moves further forward - moderate entry rocker, Speed Box mid board shifted further forward, moderately low tail rocker, moderate volume, defined profile and foil, thicker nose and thinner tail.
 
 
 
The third and final set of two images, 1990 rocker, profile, and foil and 2020 rocker, profile, and foil illustrate how incremental design improvements over time become quantum improvements. The design evolution from the 1990 Glass Slipper to the 2020 - 2021 Contemporary Performance Shortboard is dramatic. The Performance Shortboard is an evolving and well executed design.
 
 
1990 "Glass Slipper" rocker, profile, and foil - mid board Speed Box, extreme entry rocker, moderate tail rocker, extremely low volume profile with moderate foil. Evolution and devolution in an extreme design. Evolutionary as the foundation of all contemporary performance shortboards and devolutionary as an extremely impractical and difficult board to ride due to the exaggerated rocker, and extremely low volume and surface area.
 
 
2020 - 2021 "Contemporary Performance Shortboard" rocker, profile, and foil - mid board Speed Box moves further forward - moderate entry rocker, Speed Box mid board shifted further forward, moderately low tail rocker, moderate volume, defined profile and foil, thicker nose and thinner tail. An evolving and well executed design.



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MID LENGTH DESIGNS
 
 
 
April 20, 2020

Mid Length and Egg Designs Overview

The Magic Carpets of the late 60s and early 70s, the era's performance shortboards, have reemerged as todays Mid Length designs. The evolution of these designs offers very user friendly surfboards for all skill levels of surfers. The same mid length board can be a high performance design and a stable and mellow cruiser depending on the surfer. With custom designs a mid length can be as unique as the demography of surfing is diverse. Mid Length designs are practical, versatile, performance capable, and user friendly.


 
 
Michael Peterson carving on an early 70s Shortboard - 2020s Mid Length

 
One of the cornerstones of mid length designs are Eggs. Egg designs owe their origin to Skip Frye, who started developing his version of the design in the early 70s. The design offered surfers the opportunity to break away from the traditional longboard style of surfing and add the joy of carving and accelerating turns to the thrill of trim and glide. To this day, this combination of surfing performance features offers an exceptionally fun surfing experience.

Today's Egg is a functional and versatile design for all skill levels, perhaps the most versatile of all surfboard designs. The combination of performance features and the wide range of conditions wherein they're functional separates them from all other designs. Any surfer could reasonably have a "one board quiver" with a well designed custom Egg.

The performance range of Egg designs varies from marginal knee high conditions to solid - well overhead surf, from onshore to side shore to offshore, from slop to perfection. The performance features of the design are a combination of carve and trim. No matter the skill level of a surfer, a mid length Egg is a design that is just super fun to ride.


Egg Anatomy

Egg designs are a mid length, moderate to high surface area and volume surfboard. They range from 6' 6" to 8' 0" long by 20" to 22" wide by 2 3/8" to 3 1/4" thick, depending on physical features of the surfer such as their size, fitness, age, technique, performance preferences, and surfing venues. These features are also considered in the other elements of design. Egg rockers are low and continuous. The bottom contours are generally convex with a tri plane entry and wide point and a panel vee from wide point to tail. A spiral vee or double concave may be incorporated into the panel vee for extra acceleration in some designs. The outlines are full and moderately wide round pin tails. The rails mimic shortboard designs, soft and neutral at the nose and wide point to a hard edge at the fins and through the tail. Primary fin configuration is 2 x 1, although thruster and quad set ups are perfectly acceptable.

Natural Curves Eggs

Our history with Egg designs dates to the year 2000. It's a design that Rob Yuen, a true "Surf Gypsy," wanted to develop. Surfer, fisherman, drift boat guide, and arborist, Rob leaves his home in Southern Oregon every winter for an extended surf expedition to Central Baja. One of his favorite "tools" has been his 8' 0" Speed Egg. Over the years, Rob cross pollinated surfboard designs with his friends from San Diego who frequent the same point breaks Rob surfs. These style and glide masters have been disciples of the Skip Frye Egg School for decades. Returning from one of his dozens of trips to The Wall, Rob had me shape him the first version of this design in 2000 - extremely low rocker, simple round pin template, tri-plane to vee convex bottom, with a cool single fin / side bite fin configuration. Rob's Speed Egg is a versatile surfboard that carves and planes in a very wide range of surf venues and conditions. In 2010 Rob had me shape a second generation Speed Egg. At 7' 8" his new Speed Egg will be more maneuverable, offer tighter radius turns, yet maintain the glide that is key to it's function. Rob has spent years fine tuning fins for his Speed Eggs. Always the master, he recently reminded me that "style is free!" Egg designs are truly saturated with style.

 
 
 
RY's 8' 0" Original Speed Egg - 2000  
RY's 7' 8' Speed Egg - 2010

 
 
 
RY Surfing   RY

 
 
 
Scott Bass Surfing a Natural Curves Speed Egg - The Original Mid Length Speed Egg

 
We have gone on to develop and continue to evolve these designs. The Speed Egg, Rocket Egg, and Kestrel are our primary mid length designs. The Speed Egg remains the highest volume version of our Egg designs. It features the fullest nose, most surface area and volume, and most rail volume. The Rocket Egg, generally a little shorter than most Speed Eggs, features less surface area in the nose and tail creating a little more curve in the outline, a little more nose or entry rocker, and slightly lower rail profile and volume. The Kestrel is the lowest volume board of these designs and arguably could not be considered a true Egg. It features a similar outline to the Rocket Egg, similar lower rail profile, and a little more rocker throughout than the Rocket Egg.

The spectrum of these three designs from trim and glide to carve and acceleration has the Speed Egg on one end maximizing the trim and glide features and the Kestrel on the other end maximizing carve and acceleration. The Rocket Egg balances trim and glide with carve and acceleration. All three designs are practical, versatile, performance capable, and user friendly.


Links to more detailed descriptions of these designs on the NC web site:

Surfboard Classes and Descriptions | Mid Lengths and Eggs

The Speed Egg

The Rocket Egg

The Kestrel



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FLAT DECKS
 
 
 
July 3, 2019
 
 
  Flat decks are an intriguing alternative to the classic crowned decks common to contemporary shortboards. Prior to the development of the low vblume - well rockered Glass Slippers of the early 90s, flat decks were very common. Dick Brewer's designs were perhaps the finest execution of this design. Their flat decks were an essential feature in establishing a crisp profile or foil from nose to tail.

The classic flat deck designs of the 70s and 80s featured primarily convex bottoms. The classic glass slipper featured concave bottoms. When we combine a flat deck with a concave bottom we're maximizing volume at and near the rails. This produced a relatively stiff board that didn't go rail to rail with ease. Concave bottoms contours and their performance features were here to stay so surfers and shapers gravitated to crowned decks of varying degree to facilitate rail to rail transition which is essential and at the core of shortboard performance.

A few years ago my shaping mate, Dave Beck and I, needed a break from work. He brought a beautiful 9' 6" RB Gun to the shaping room. The board had a very crisp flat deck and foil. It was an eye opener. That board got us thinking about reintroducing some flat decks into our designs. (see illustration below)




What do flat decks bring to our design resources? One of the most obvious features is the additional volume it brings to a shape when all other variables are held constant. The deck is simply fuller side to side thus adding volume. (see illustration below)



This image illustrates the extra volume in a flat deck. The volume of the flat deck board is 32.5 Liters - the volume of the crowned deck board is 31.5 Liters.

Flat decks also add an element of stability to a board. A deck with more volume towards the rail will not tip or roll side to side, or rail to rail, as easily as a classic crowned deck which is thicker at the stringer and thinner in the rails.

How can we effectively integrate flat decks into contemporary designs? That will vary by the over all design, the venues, the conditions, and the surfer, and the surfing the boards are designed for.

When increased volume and stability are the primary design considerations simply redesigning the deck from crown to flat will yield a strong paddling, wave catching, stable, speed generating, and speed maintaining board. These features would be an asset for several conditions and surfers.

(1) Boards for larger surfers, older surfers, or surfers who are transitioning from mid range boards to short boards all of whom could benefit from more volume in their boards.

(2) Boards for waves with marginal energy where extra volume will help generate and maintain speed and ultimately maneuverability.

(3) Boards for XL and XXL waves where extra volume and stability are essential to paddling mobility, wave catching, and stability and flow in heavy water conditions.

When performance is the primary design consideration, flat deck designs offer excellent and unique performance features in moderate and lower volume designs. We have already established that holding all other variables constant a flat deck will increase the volume of a board. (see illustration below)




If we want a flat deck board with equal volume to the otherwise same board we must reduce the thickness of the board to achieve that same volume. Reducing flat deck volume to equal crown deck volume by thinning a board can yield a very well tuned high performance board. (see illustration below)



This image illustrates the reduced thickness of a flat deck required to yield equal volume as a crowned deck. The volume of both boards is 31.5 Liters.

The stable nature of a flat deck design offers yet another very functional design option. Reducing the volume even further can yield a design that combines the stable feel of a flat deck with the performance we associate with a crowned deck. (see illustration below)



This image illustrates reducing the thickness of a flat deck board to yield the same rail volume as a crowned deck board. The volume of the flat deck board is 29.5 Liters - the volume of the crowned deck board is 31.5 Liters. The thickness of the crowned deck board is 2.18" - the thickness of the crowned deck board is 2.35."

After several years of experimenting with flat decks we find these designs most appropriate for small wave boards such as Fish, NC Malolos, and NC Merlins and for XL and XXL wave boards such as Semi Guns, and Guns. The extra volume and stability in these designs are a great asset to the unique performance demands of each of these designs.



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SINGLE & DOUBLE CONCAVES
 
 
 
May 1, 2019
 
 
  Surfers are familiar with the common concave bottom contours in contemporary shortboards. The most common concave arrays are single concave entry to tail and single to double concave entry to tail. Concave shapes have more curve in the rail line than along the stringer. The additional curve in the rail rocker dips below the rocker along the stringer. This intriguing juxtaposition of curves creates concaves. Concaves increase the surface are of the bottom of a board and amplify laminar flow. Both of these feature generate lift and reduce drag.


Single Concaves offer the surfer acceleration, speed, projection, and maximum maneuverability. Single concave designs are a very fast and loose botom design. The simple clean rail to rail arc of a single concave provides lift and reduces drag. Occasionally, a single concave will have a touch of double concave or vee in the last 4" to 8" of the tail. This short double concave adds an element of control and release. Moving such a double concave forward in the bottom contours yields the classic single to double concave.

Single to Double Concaves offer, in addition to acceleration, speed, projection, and maneuverability an element of control to a board. The "spine" along the center of a double concave sustains the flow of water down the length of the bottom of a board, maximizing laminar flow. The peak and the depth of the spine of a double concave can be moved forward or back and deeper or shallower to fine tune manuverability versus control. A clean double concave also provides lift and reduces drag. The element of extra control from the spine of the double concave makes the design a great bottom contour option for good wave Shortboards, Step Ups and Semi Guns.

Concaves are a radical design feature. They generate lift and reduce drag. They offer acceleration, speed, projection, maneuverability, and control - all depending on surfer input. They may have different configurations, different depths, and different placement in a shape. Their radical nature allows surfers and shapers to tune performance by their configuration. A well designed concave array maximizes concaves' positive features - acceleration, speed, projection, maneuverability and control.



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TUNING & DETUNING RAILS
 
 
 
October 10, 2018
 
 
  Rail are defined by their profiles, their apex - the mid point in the rail profile between the top and bottom of the board, and the bottom corner of the rail where the rail profile meets the bottom of the board. All aspects of a surfboard's rails are integrated to create a rail that best suits the purpose of the board's design.

Link to a description of rails.

When designing boards for a variety of conditions we can vary the tuck and edge of the rail from wide point to tail to dial up or dial down generating acceleration and speed or controlling acceleration and speed. The further we tuck the rail into the bottom of the board the more the board will sit down in the water and conversely, the less we tuck the rail into the bottom of the board the more the board will sit on top of the water. The more the board and rails sit down in the water the more control a surfer will have making a full rail turn or in high speed trim. The less a board and rails sit down in the water the more speed and release a board will have in small and or marginal conditions.

The length of the machine like hard edge carries from the tail towards the wide point has the same affect as the tuck of the rail in this area. The shorter this edge is, where the edge blends to a soft tuck from the tail, the lower the board will sit in the water and the more control the board will offer the surfer in solid and quality conditions The further this edge carries towards the wide point the higher the board will sit on the water and the more speed it will generate and release it will offer in small and marginal conditions.

Ultimately, the performance features of the tuck and edge of rails allow us to dial up and down speed and control in all our designs. Boards for small and marginal conditions will benefit from less tuck and more edge. Boards for all around conditions will have a reasonable blend of tuck and edge. Boards for quality waves, heavy water, and big waves will benefit from more tuck and less edge.



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2017 ROCKERS
 
 
 
March 28, 2017
 
 
 
2017 offered us opporunities to explore and evolve surfboard design. Surfing Kauai that winter with surfer / shaper Dave Beck and test pilot Randy Davis fired me up to work on rockers that will fit in the parts of waves that offer the board and surfer the greatest opportunity to tap into the energy a wave has to offer. The theory of creating rocker that fits into critical sections to generate speed and power dates to the dramatic short board design revolution of 1966 - 1969. Surfboard design focused on trim to that point. Over night the focus pivoted to radical, high speed turns with surfers accelerating in and out of the pocket and from top to bottom of waves. Pretty amazing surfing compared to the elegant dance of trim and nose riding.

The Modern Surfboard for the convenience of this discussion dates to the early 20th Century and the designs rode by Duke Kahanmoku, Tom Blake, and other fortunate surfers. These designs focused on trim. They were very long and relatively flat and thick. They had a lot of surface area and a lot of volume. Surfing and surfboard design did not shift it's focus beyond trim, nose riding, and steering boards around as much as turning them until the mid to late 60s. Short board pioneers changed all that from 1966 to 1969. Surfing and surfboard design focused on high speed turns, accelerating in and out of the pocket and up and down the face of waves. Boards were shorter, narrower, and thinner. They lost considerable surface area and volume - key elements of trim and nose ride designs. The loss of surface area and volume resulted in less energy juiced into boards and surfers were required to find new techniques for taping into the energy in a wave. This was a primary factor in the evolution of tail rocker in surfboard design. A design that fit effortlessly in the tight, critical sections of a wave had the ability to tap into the abundant energy a wave had to offer.

Low, nearly non existent tail rocker carried over from the last of the highly evolved LBs to the first short boards. Surfers and designers were still attached to the low tail rocker profiles. The developing problem was that these rockers did not fit well into the parts of waves that surfing was now exploring and ultimately these designs were not as effecient as they could be. Realizing that more curve was required for a board to fit into the pocket of waves a few surfer / shapers started to incorporate rocker into their shapes that mimicked the curves we find in the most vertical part of any wave. These curves allowed boards to tap into the waves' energy and ultimately allows the surfer to maximize all the performance possibilities on a wave.

2017's early rocker ideas started when RD brought up performance when redirecting or down carving into the pocket on fast vertical waves. Initially we thought adding tail rocker over all and increasing curve in the rocker segment from wide point to tail would offer better release in this critical moment. DB entered the discusion pointing out we did not want to risk losing acceleration, speed, and projection as a result of this rocker adjustment. Ultimately, we developed a curve that maintained the speed box properties through the wide point to the center of the surfer's stance and added the accelerating curve we wanted to incorporate from that point through the tail.

This rocker is a Speed Box with an accelerated tail rocker. It's not intended to be a specialty rocker - that is designed for specific conditions. Specialty boards are great, but by their nature may only excel in a narrow set of conditions. It's simply a step in the evolution and development of rockers for all conditions. It's a design option that will continue to perform well in moderate and all around conditions, but will excel in vertical and hollow sections of high quality waves.



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