CJ Surf Designs


Uniquely Different ~ Crafted for the individual.

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Pulse Asymmetric

Asymetric Both Web


Why Asymmetric?

An asymmetric shape allows you to further optimise a board for use in the dominant conditions where you usually sail. They’re a lot of fun even if you only get to sail mostly onshore wind swell conditions but in classic cross off ground swell conditions they add a new dimension of performance. I’m fortunate in that my home spots lie along the west Cornwall coast and has me mostly sailing at Gwithian, The Bluff or thereabouts and heading out on port tack most of the time.

I built a few asymmetric boards for myself back in the mid 80’s when they were very popular in Hawaii. Most people thought they were a bit of a nonsense for the typical UK wind wave conditions but once I’d built and sailed one I was sold on the idea. I’ve long tended to enjoy building things a bit different to ride myself because I learn so much from this experimentation.

New and Old

In those days I built for my local Brighton, UK, south coast conditions (Including the board pictured on the right from…er 1985!) and found them huge fun because of the way they turn so differently on each tack. Every board is a compromise but an asymmetric does allow you to create a board that is less of a compromise relative to your local conditions. The basic premise being that different shapes work better for hi speed bottom turning compared to slower more pivotal top turns, be that in quality surf or mushy wind waves. I’ve seen one or two asymmetric boards pop up on the web in fairly recent years, most notably one from the legendary Mark Angulo and well maybe it was time for me to revisit the design as well.

My final inspiration for actually building this board came with the arrival of my new Hot Sails MauiKS3 sails last autumn. The super responsive, tight turning, yet forgiving, direct and powerful nature of these sails instantly had me wanting a new totally wave focused board tuned to their new school performance characteristics. It also had to be extremely user friendly for someone with less skills than Kauli Seadi! Secondly it has to deal well with the often heavy chop, gusty winds and strong tides that typify my local conditions.

Starting point is volume, 85 litres, equal to my current weight in kilos. Experience has shown that a board of around this volume to body weight ratio rarely disappoints and is well matched to the gusty cross off conditions it’ll mostly be used in. Length is 232cm, I could have gone shorter by rounding off the nose more but I want those few extras centimetres of nose kick that ease the way out over white water and can save you from some nasty pearling situations. Principal dimensions are pretty typical for a modern 85 litre wave board at around 58cm width, 36cm tail and 42cm nose. However, when you consider that if built as two separate symmetric boards then the bottom turning side one would have been nearer 56cm, 32cm and 40cm and the wide style top turn side at 61cm, 40cm, 43cm you can begin to grasp some of the differences. (On the diagram above the red line shows the outline and profile of the narrow side)


Much is achieved from this. For speed and control on the downwind, bottom turn side, the outline is drawn out with the wide point forward of centre and a narrow tail thus giving a longer, straighter rail line to engage into and through the bottom turn. This makes it easier to confidently set your rail at full chat, and provides excellent grip, speed and chop control through the turn. Whereas the wider more curvaceous side has the wide point at centre and a much wider tail creating more curve in the outline. This encourages a tighter turning arc due to the shorter length of rail engaged as the board is banked off the top and gives more volume and lift to help accelerate out of the turn. However as the overall tail width of the combined outlines still remains a moderate 36cm you don’t have to contend with the low speed problems of a narrow tailed wave board or the high speed problems a wide wave board has.

The foot straps are set off centre according to the final dimensions of the board but central to the actual join line between the two outline templates. This results in the rear strap being significantly closer to the rail on the bottom turn side which again helps with setting up, into and through a high speed bottom turn. The forward straps are positioned differently as well with the front foot further forward on the bottom turn side again to promote full rail turns. There are many more subtle details and differences as well in terms of bottom profile, wave orientated rocker curve, volume flows and rail profiles that are beyond the scope of this overview.

Although asymmetric in design none of these differences are extreme enough to make the board so radical that it couldn’t happily be sailed on the opposite tack if needed and I’ll be blatting about on it at starboard tack Marazion from time to time for sure.

Fin Positioning

I opted for a three fin configuration as I feel this gives the most varied tuning options and minimum drag. The side fins are toed in in such away that they align equally relative to the centre fin but differently from each other which balances them with the water flow and respective tail width and outline differences where the wide side fin is set closer to the rail.

Black Project Fins make some of the finest fins you can buy and I don’t know of anyone who hasn’t been delighted when they’ve tested them. The designer, Tom Hammerton also had significant input into the design of the Hot Sails MauiKS3 sail so it seems only natural to match these fins with the sails. I aim for just enough fin area to do the job required which means less area with high winds and small sails and more area with lower winds and bigger sails. Black Projects are very efficient for their size and I find I can easily go for smaller sizes than I could on my old fins. For straight ease and get up and go a large centre fin and small thrusters is probably favourite but as I’m more focused on looseness and wave performance with this board I’ve started with a compact spread of 15.5cm Mini Epic, plus a Thruster 10cm on the bottom turn side (similar to half a Quad set up) and a Wave MultiFintastic 11cm on the top turn side for pivot and drive off the top. This gives quite a low surface area of 244cm2 and judging by my first outing with a 4.9m2 sail in pretty weak waist to chest high waves this works really well when fully powered but is a bit lacking in lighter winds. Depending on wind strength the next outing will be with larger side fins at 11cm and 12cm plus the 15.5cm, to give just a little more drive and area at 267cm2 but very little, if any, perceptible loss of looseness. The difference changing fins can make should not be under estimated. If in doubt try a set a bit smaller than those that came with your production board because I think many production boards are biased towards being over finned to make them as instantly user friendly as possible to a wide variety of buyers.

Construction is a tough full carbon/kevlar, pvc sandwich, over H glass with selective carbon/dyneema reinforcements and weighs in at a pleasing 6.6kg bare. The fabric is carbon dominant giving high strength and stiffness but with the additional kevlar to improve impact resistance. I set myself the challenge to work very precisely and with no filler to utilise the beauty of the carbon/kevlar fabric as the main cosmetic feature of the board. The second challenge was a high gloss finish to enhance the full beauty of the fabric and a simple but effective graphic to tie in with my sails. As a point of interest the gloss finish added less than 200gms to the final weight. Your typical super sanded finished boards are more about labour and cost saving then weight saving.

The end result is something I’m proud of that is highly functional, huge fun and uniquely different. Now when is the next decent forecast…!


Must tighten the battens

Come On!




Here’s something a bit different – a light, tough, compact, 92ltr, flex tail, single fin wave board.

Why build that? Well the theory is as follows. Multi-finned boards maybe a lot of fun but those fins increase drag. Yes they can generate drive and assist turning etc. but on other points of sail they just add drag from their high wetted surface area and increased turbulence, hence there are no multi finned speed or slalom boards. This inefficiency troubles me a little so I’ve revisited an old approach and added flex to improve turning response and paired that with the pure efficiency of a single fin.

kapow hull

My target is to combine the many advantages a reduced tail rocker gives on a sailboard (early planing, speed, windward performance, and drive in longer turns) but with the tighter turning benefits of increased tail rocker as needed. I also gain from the pure hydrodynamic efficiency of a single fin and its free flowing feel that I really like. Another particular attraction is the great ease of switching fins to tune for different conditions. This board is primarily designed for use with the fast, stable and free turning Black Project Epic Wave 21.5cm fin in cross offshore conditions (Gwithian etc.). However I can swiftly swap to the slightly more pivotal Black Project Wave Single 22cm for side/onshore days (Marazion) and finally the powerful Black Project Freewave 24cm for jumping and general blasting about in weak wave or free ride conditions (Carrick roads, Gyllyngvase).

Three easy fin choices that change the feel of one board to cover most of the conditions Cornwall sends my way, with more predictable performance gains and far less hassle than swapping multi-fins about. Singles may not be as “current” as twins, thrusters or quads but nevertheless they still work really well and make a lot of sense for highly changeable UK conditions. Add the advantages of variable tail rocker I think I maybe onto a winner ~ for my needs at least.

Black Project Fins Wave Singles from CJ Surf on Vimeo.

I really enjoy my “Maza Fish” quad design and that was the starting point for this board. That board was intended primarily for summery 5.7m weather but even so I’ve ended up using it a lot in high winds and in some decent sized waves simply because of how user friendly it is. This new smaller board is to be my board of choice for most of the 4.7 to 5.3 days. “Kapow” has a modified outline and is narrower and shorter at just 2.26m x59.5cm (Maza Fish is 235 x 61.5). I’ve increased the nose rocker to add ease and confidence in chunkier conditions and to bring more rail rocker curve into the forward entry of the board to further improve turning and manoeuvrability (the entry rail rocker has a large effect on turning due to the way it drives the front of the board round when the forward rail is engaged); otherwise the rest of the rocker line follows a similar but mildly increased curve.

The negative side of this entry rocker is that the board will be a bit more “sticky” when stood forward slogging out in lulls, and to help offset this I’ve kept plenty of volume up front so that it rides high at slow speeds and to compensate for the reduced length. I’ve then carried as much volume as I dare through into the tail so that I can get quickly back and “pop” the nose up and away in a gust to get into planing mode. Underneath we have a fairly standard double concave running into v which gives excellent chop control, tracking and planing. Careful carbon/dyneema laminates, Textreme reinforcements, minimum paint and no filler has the weight down to a respectable 7.00 kg fin, straps and all.

The unusual bit is the modified swallow flex tail configuration that allows each side of the tail to flex differently in response to rider input, so that the inside edge can curve more into a turn whilst letting the outside edge stay straighter and continue to provide more drive. Over the years I’ve dreamed through all manner of whacky ways to add flex into a board in only the places where I want it (if the whole board bends it’s simply horrible to sail) but the great challenge is achieving this without adding excessive weight, complexity, or fragility.

My solution with this initial experiment has been to keep it very simple and opt only for flex behind the fin. To do this I cut away the upper tail section part way through build, reinforced the flex section with unidirectional carbon fibre and filled in the gap with soft closed cell foam to maintain tail volume. Other flex tail designs that I’ve seen have appeared overly easy to flex, which to my mind means you’ll lose lift and generate drag from the tail too much of the time. I want good stiffness and rebound to help give lift and drive and I’m only seeking a relatively small deflection in order to alter responses moderately. Indeed I have already re-worked my first version of this tail into a stiffer configuration as I felt the mark one was too soft. (The video below shows the mark one, it’s now stiffer but you still get the general idea)

Flex Tail 2013 from CJ Surf on Vimeo.
Does it work? Yes! It’s early days but after half a dozen outings in varied conditions it’s clear that the board has the driven, less skatey single fin style that I like but also turns very well, is fast, responsive and romps upwind. As you might expect it’s sensitive to back foot pressure and I’m having a blast learning the board and how to trim my weight inputs.

The low weight is an added bonus when coupled with my lightweight Hotsails Firelights and Chinook rig components. Everything feels highly responsive and less fatiguing due to the lower inertia.

I’m not claiming any revolutionary game changer here; it’s simply an interesting project resulting in a super fun board to sail in a wide variety of conditions.

My abilities limit it’s performance rather more than the reverse. A dedicated tri/quad version could be awesome as well, so maybe…..

Flex tail deck

The “Maza Fish”

Mazza Fish Quad
Here’s a board thats especially fun for those oh too frequent average days with less than perfect waves and wind.

Maza Fish deckIf you’ve windsurfed at any of the main Cornish breaks you’ll have noticed just how gusty and full of holes the wind tends to be. UK frontal winds are gusty at the best of times but ask this already gusty wind to cross over the Cornish peninsular and blow into the top spots in Mounts or St Ives bays from a side or cross off direction and some seriously unstable winds result, not simply gusty but also full of major holes. When I first sailed here on my smaller Sussex coast equipment I found it maddening, sail, sink, sail, sink, wave…. it was like learning all over again. I’m 90kg and used to be pretty happy sailing 80ish litre boards much of the time but now, here, I’d reserve a board of that size for 4.2 weather and even then sailing could still be too start/stop for it to be that much fun. Of course there are many options and some wave purists choose to put up with very difficult slogging out with little or no jumping for the pleasure of wave riding a smaller board. I mostly prefer to be sailing, not sinking, and indeed one of the great bonuses of windsurfing over surfing is how much fun the heading out part is compared to duck-diving and paddling. For me the holy grail of board design is to create a bigger board that feels or behaves as responsively as a small board or vice versa.

Most of the standout sailors in these parts are riding gear of a volume at least equal to their kilo weight in litres and very often 10+ litres floatier. Local Goya team ripper and extreme jumper Andy King (84kg), for instance, is frequently seen riding 100lt+ freestyle or freewave boards to devastating effect on the more mundane days. The gust tolerant early planing qualities of these boards mean he gets way more jumps and waves than the “slog and ride” brigade; he’s just all over the break, having heaps of fun and instantly stands out from the rest.

Maza Fish_bottomWith multi finned boards it is possible to build a bigger board that handles more like a smaller board and that is the intention with this design. I get the benefits of the easy planing lift of a wider, floatier, straighter rockered board but with less of the stiffness associated with a single fin board of similar design. With a large wide tailed single fin design the board turns around the centrally placed fin but with a twin or quad the board turns a tighter radius around the fin(s) on the inside rail and feels looser. Smaller fins positioned off centre also reduce the rolling resistance of the board from rail to rail when compared to a bigger single fin which again frees up the board. The main down sides compared to a single will be lower top speed and less instant low speed bite and drive, particularly in foam, but I can live with that for a more chuck around manoeuvre oriented feel.

The board has a “fast tail” type of rocker where the section from a little aft of the front foot straps straightens along the centre line of the board into the tail. This promotes speed, early planing and drive through turns as it far less “sucky” or drag inducing than a tail kick type of rocker but to avoid the board feeling just too stiff and pivotal more rocker is introduced into the rail outline through the use of vee that increases into the tail so that as the board is banked into a turn more rocker curve is presented.Maza Fish_fins Through the mid sections my preferred double concave with a slight vee profile is used to soften the ride and promote control with good planing. The curvaceous outline presents a shorter rail waterline when the board is banked promoting tighter turns. I’ve carried plenty of volume into the tail to help the board keep going through lulls and low speed turns knowing that the added bite provided by the multi fins and swallow tail will help reduce any tendency for bouncing out in chop.

So we have a quick, responsive, compact and floaty, wave board perfect for gentler summer swells in Cornwall and spots like Marazion (aka “Maza”). I’ll call it the “Maza Fish” and just for fun lets put a mermaid on the bottom (Design by Rosamunde Parsons). Construction is full carbon/dynema PVC sandwich bottom with a paulonia wood carbon/dynema glass sandwich deck and carbon rails. At 7.5kg bare its still heavier than I want but super tough and tough is good. It also gives me a versatile platform for experimenting with different fin configurations and I’m particularly keen to try some asymmetric options.

Aerial at Gwithian


Wave Single 87lt

CAD 87CJ 87 HiWindCJ 87 TailHaving ridden my bigger 95lt board for quite sometime I built up further ideas for what I wanted as a replacement to my current smaller board (A Proof custom). This is my board for use on higher wind 5.0 /4.7/4.2 type days and for the bigger and better down the line wave days, yet still with enough float to get me through the lulls and massive wind holes we suffer from around these parts. Dimensions are 235 x 58 and 32.5 tail. It’s a challenge to design a compact yet fairly floaty board that doesn’t handle like a cork, but by combining vee and concaves to soften the bounce in chop, along with doming the deck to keep volume out of the rails, the board floats well but also bites hard into a turn with remarkably little bounce. I also wanted a narrow tail because of the extra control and response you get at speed. The decent 58cm wide point forward width aids volume distribution and generates plenty of low speed lift to help with slogging out and planing. The zero point of the bottom curve is centred beneath the front foot strap so the board balances and rail steers from directly under my front foot, with the board planing aft from there on the narrow single concave tail to give the feeling of a smaller board. Again the rail line rocker follows a more pronounced curve than along the centre of the board thus increasing the turning response as the board is banked. This board is huge fun to sail and I’m only just getting to know it. It’s due to morph into a 2 + 1 fin configuration in the coming months.

Wave Single 70lt

CAD 7070 Single Deck70 SingleThis was built for respected local sailmaker (RB Sails) and ripper Ian Ross. Ian is in no rush to jump on the multi fin bandwagon without further research and development so we started with this classic driving 70 ltr. single fin at 228 x 52.5 with a 31.5 tail. Ian likes to put himself into gnarly situations sailing “secret” Cornish reef breaks and so requires a tough, predictable and dependable board. This carbon/dyneema bamboo decked board bottom turns as if on rails and just flows along a good wave, it’s quick planing with a smooth chop conquering ride, whilst also strong enough to bounce off a rock or two when things go wrong.  Ian has many friends in the industry and gets to try a lot of different boards and his input is very useful in developing shapes.

CJ 70 Single

Wave Single 95lt #2

Design 95_2
952 Deck952_botHaving been a little surprised by the end weight of my previous build I bought myself a very sensitive set of scales on which to weigh each layer and process of construction. My boards have to be light and strong and for a 95lt board 7.5kg all up is a fair target, this board came in at 7.6kg which I’m pretty happy with. The design is a little more all round and a tad less intensely wave riding focused than the mark one. I’ve found that my favourite boards have been the less extreme ones that you use a lot and get to really know well. It’s always tempting to try and build the “perfect” board for the “perfect day” but actually the perfect board for most days is a far more usable target. Sure you want a perfect day board but that shouldn’t be your first purchase. So to this end I widened the tail (36) for more early planing lift and to hold speed through lower speed turns and also because I intend to experiment with multiple fin combinations once I’ve got to know it really well as a single. I see quads in particular as being very useful in making larger boards behave more like smaller boards and whilst the outline of this board isn’t necessarily optimised for a quad fin set up I’ll still learn a great deal from the experiment. The wide point (58.5) is just forward of centre helping to give a generous amount of  rail curve into the tail, thus giving a shorter wetted rail line for tighter (though more pivotal) turns, with the volume (95lt) well balanced between nose and tail. It’s still a wave biased board with a generous even rocker and rolled vee through double concave to vee bottom. Full carbon/dyneema foam sandwich construction and a simple paint job. I’ve been having a lot of fun with this board.

Wave Single 95lt

CAD 951
Windsurf 1My first outing into composite sandwich construction where I set myself a fair few challenges. After much research into the latest composite fabrics available I concluded that carbon/dyneema hybrid reinforcement offered the best combination of strength and durability. Carbon/Dyneema is costly and an absolute sod to work with but it is super tough stuff and in my opinion worth the additional challenge.

I also love working with wood and the natural beauty of it so to add to the challenge let’s see if I can incorporate a paulownia wood sandwich deck. Paulonia wood is light, very strong, water resistant and highly sustainable except for the fact that it has to be imported from overseas.

Design wise I wanted a board that would float my 90kg yet ride waves very smoothly and predictably; the focus is directed more towards “slog and ride” than the typical early planing freewave boards so common in this size bracket. No twins or quads yet, I didn’t care for the twins I’d tried so far and being a bit old school anyway I just love the look and feel of single fin flow. I’ll be building quads again for sure, I had a lot of fun building them back in the 80s after all.

The 59.5 cm wide point is pulled forward giving a fairly straight rail that is very grippy into the relatively narrow 35cm tail. The width forward also makes for easier tacking, slogging out and getting into a wave. The diamond tail is there more because its a bit unusual and I liked the retro look, than for any particular performance target. The volume is distributed evenly under a domed deck with soft low rails designed to bite but not trip. Bottom shape is the tried and true rolled vee in the nose through to double concave vee through the midsections and into straight vee in the tail. This shape not only gives a very smooth free planing ride but also creates a different rocker line along the rails so that as the board is banked it turns tighter along the rail. The design rocker line is an amalgamation of things learnt from my favourite boards of recent years. Unfortunately my learning curve with vacuum sandwich construction meant the end result was not the rocker curve I’d designed…doh! But hey, it was my first vacuum sandwich board….

Welcome to the world of vacuum bagging!

There’s mountains of information about vacuum bagging online and all manner of companies selling all manner of products and consumables that you may or may not truly need. On the face of it it looks to be an extremely wasteful process with metres of assorted tapes, plastics and disposable fabrics apparently intended to be used just once. I can’t accept that from a cost or an environmental perspective so I studied some more, spoke with boat builder friends (I’ve been in the yacht construction industry for 20+ years) etc. until I figured I’d found a reasonable compromise. Anyway, after much angst, gnashing of teeth, cursing of pin holes and more dramas than you’d ever imagine I got the board all sandwiched and laminated up and really looking pretty good BUT weighing in at a whopping 9.25kg finned and strapped. Let me tell you, you really feel 9.25 kg when compared against a similar sized board at 7.5kg. The added mass and momentum can be quite enjoyable on a wave at times but come airtime its not welcome at all. Combine this weight with the unintended extra tail rocker and performance is just a little too sluggish. So this little baby has become a wall hanger…..I sure learnt a lot from building it though.

Windsurf 951
CJ Water 1