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"It paddles well, fast but not too tippy.  I am able to keep up with the racing K1 at the local canoe/kayak club, and it definitely is eye-catching on the water.  I am very happy to have chosen the ‘Spray’ design."
Mark Tremorrow


Images | Particulars | More about | Background and history

Plans, Spray - 130 EUR Purchase

Spray, designed in 2014, is a shorter, wider, and more initially stable surfski version of Spindrift– for those who would sacrifice a little top speed for stability. Anyone used to sea kayaks can paddle Spray, and enjoy the speed, handling in waves, and surfing capabilities. It may take a short while to get used to the open cockpit instead of being squeezed in between back, thigh, and foot supports.

Take a look at Roger Karlsson's photo diary (Swedish only) from his Spindrift project,
or dive into Jose Francisco Yuste Ramirez' very ambitious Spray project.
or Per Carlins building pages with discussions on material and methods (Swedish only). 

More stability?

After a couple of requests for even more width/stability, I have prepared an alternative station drawing, with 54 cm beam (the same beam as fx Epic V8). If this is what you want please note "wide" in the alternatives field when ordering. On the lines and construction drawing the cockpit is 2 cm wider, but apart from that unchanged – other dimensional changes must be done individually by the builder if necessary. But you should weight 90 kg or more, or always paddle with a touring load to choose "wide" – otherwise, you will float too high and lose stability through higher CG and less waterline width.


Eric Anhage, SpraySpray – Eric AnhageSpray – Eric AnhageSpray – Eric AnhageSpindrift – Robert RusselTwo New Zealand Spindrifts and a Spray on the water. Photo: Lockie Russel.Two Spindrifts and a Spray in New Zealand, built by Robert Russel.The Russels with their Spindrifts and Spray. Photo: Warwick Russel.Spray – Roberto Yañez Vargas, Nautilus KayaksSpray – Roberto Yañez Vargas, Nautilus KayaksSpray – John FulkerSpray – John FulkerSpray – John FulkerSpray – John FulkerSpray – John FulkerSpray – Per SkräddarsSpray – Per SkräddarsSpray – Per SkräddarsSpray – Per SkräddarsSpray – Per CarlinSpray – Per CarlinSpray – Per CarlinSpray – Per CarlinSpray, built by Dan Caouette for Jim in DetroitSpray, built by Dan vaouette for Jim in DetroitSpray, built by Dan Caouette for Jim in DetroitSpray – Torbjörn SvenssonSpray – Torbjörn SvenssonSpray – Torbjörn SvenssonSpray – Björn AnderssonSpray – Björn AnderssonSpray – Björn AnderssonSpray – Björn AnderssonSpray – Björn Andersson


Spray, lines

Length¹ 560/556 cm (overall/WL)
Beam 50/46 cm (overall/WL)
Draft 11 cm
Cockpit¹ 132x40 cm
Height¹ 31/23 cm (in front of/behind the cockpit)
Weight² 15-18 kg
Displacement/volume⁶ 110 kg/374 litre
Speed³ 8.7/12.8 km/h
Prismatic coefficient 0.54
Wetted surface 1.97 m²
Drag⁴ 1.28/2.32 kp
Stability⁵ 3/4 (initial/secondary stability)
Intended use Motion och långfärd till havs och i sjösystem
Length¹ 560/556 cm (overall/WL)
Beam 54/50 cm (overall/WL)
Draft 11 cm
Cockpit¹ 132x42 cm
Height¹ 31/23 cm (in front of/behind the cockpit)
Weight² 15-18 kg
Displacement/volume⁶ 118 kg/400 litre
Speed³ 8.6/12.6 km/h
Prismatic coefficient 0.54
Wetted surface 2.11 m²
Drag⁴ 1.29/2.36 kp
Stability⁵ 4/4 (initial/secondary stability)
Intended use Motion och långfärd till havs och i sjösystem

* These dimensions can be adapted to suit personal needs or wishes.
** Depending on type of wood, equipment, care with epoxy usage, sanding etc. etc.
*** The speed numbers are based on mathematical standard formulas (175 lb paddler + 30 lb carco weight) and corrected from the kayaks actual performance om trials, on tours and in races.
⁴ Calculated resistance in 4 and 5 knots (at nominal load capacity).
⁵ Initial stability and secondary stability on a subjective scale, where 1 is very tippy and 5 is very stable.
⁶ Displacement is kayak + paddler + load. Count off the kayak weight to get the load capacity.


The plan sheets contain the information needed to build the kayak/canoe. Station molds, stems and construction details are full scale. For kayaks the recommended cockpit size is shown half scale with offsets for a full scale drawing and advice on altering the size. On the plans you will also find advice on how to shorten or lengthen the craft. Lines and construction drawings are in metric scale 1:10.

Spray, plans

The illustrated step-by-step building manual is in Swedish only, but it is available online in English: it covers all steps in detail and will guide first-time builders through the project.

Plans, Spray - 130 EUR Purchase

Minimum window dimensions to get your kayak out from the workshop:

Why a surfski instead of a sea kayak?

There are of course good reasons for both. They do the same job and there is not much that cannot be done in both. I think that surfskis will take over some of the sea kayaks' territory. Perhaps we will declare rudder-dependant sea kayaks, multisport kayaks, and training kayaks to be 'endangered species' in a few years? Surfskis can be considered a step forward as a kayak concept. Consider the following:


The safety routines in a ski are easier to master than comparable routines in a sea kayak.

  • Reentering the cockpit from the sea is a straightforward and quite simple procedure that takes a couple of seconds and is made the same way in all conditions. Since it is very quick, there is less risk of getting cold or tired, and there is no need to pump – with no deck, most of the water splashes out when entering and the rest drains as soon as you start paddling.
  • A surfski is basically a simpler craft with fewer components that can break or malfunction, and the few which need adjustment – the pedal setup and the drain – are within reach in the cockpit.
  • A surfski is an efficient craft; fast and light – but it is not just about speed. Just as important is conserving energy, whether long-distance touring or racing and still having the strength to deal with a headwind or adverse current at the end of the day.
  • A surfski is controllable in conditions where a sea kayak is hard to control. The reason is efficient steering: solid pedals and big efficient rudders (I never thought I would actually say that ;-). An elliptical rudder two or three feet from the stern on a highly maneuverable surfski is far more efficient than a stern-mounted rudder on a sea kayak, and the surfski’s solid and precise pedal control with no flex is much better than the rudder arrangement on most sea kayaks.

Fun to paddle

A surfski is exciting on the water. In addition to all that most sea kayaks can do, the surfski offers downwind runs in rough seas with amazing surfing under full control and at speeds well above what even a very fast kayak can achieve. With a surfski, a paddler can play in breaking waves the same way as a board-surfers do.

Simple to use

The surfski invites a minimalistic approach: fewer gadgets to buy, pack and unpack during trips, and less upkeep. That leads to less weight, better performance, and quicker launchings.


A surfski is an excellent exercise and training craft. Of course, a sea-kayak can provide an efficient workout – provided you don’t slouch against the backband and arm-paddle – but the surfski’s simplicity makes it easy to get on the water. Head for the shore with the light surfski on one shoulder, paddle, and PFD in hand launch and away you go...

Sea racer or surfski?

What is the real difference between a fast kayak (Sea Racer) and a surfski (Spindrift, Spray)? What separates surfskis from sea kayaks or multisport kayaks?

The only sure identifier is the cockpit configuration. In everything else there are lots of crossover boats floating around, defying categorization: sea kayaks with surfski maneuverability and surfski with the calm movements of sea kayaks and a variety of hull configurations.

Surfskis were developed to run off the wind on large swells at high speed and to surf wavefronts in control. To maintain position and direction on those waves, extreme maneuverability was needed, and this required precise steering and a relatively large rudder. The high-volume bow prevented diving in the gigantic waves of the surfski’s native waters in Hawaii, South Africa, California, and Australia. Meanwhile, the stern often became little more than a long tail with a rudder. The fore part was deep and narrow moving the center of the lateral area forward to balance the large rudder while the aft part was wide and shallow to prevent the stern from submerging at speeds close to or above hull speed. From tools for elite paddlers in tough ocean races, surfskis have evolved to include craft more suited to "normal" paddlers with fast-touring ambitions.

In contrast, sea kayaks for touring have evolved towards strong tracking, rather than maneuverability. Designers have sacrificed some maneuverability for comfort on long passages. In automotive terms, they have the soft, somewhat imprecise steering with a healthy margin for errors of a family car, rather than the precise and attention-demanding steering of a race car. Of course, some control is lost in the process. If you have tried to surf a steep wave diagonally in a typical sea kayak, you will know what I am talking about. But lately, we have seen a lot of sea kayaks with almost surfski-like maneuverability and control.

A look at the lines of the Sea Racer and Spindrift/Spray reveals these differences. The Sea Racer hull is more symmetric, with LCB, LCF, and CLA quite close to the center, characteristic of a hull that moves smoothly and predictably in the water (LCB = Longitudinal Center of Buoyancy = the centroid of the underwater volume of the boat expressed as a longitudinal location. LCF = Longitudinal Center of Flotation = center of the waterplane, the "seesaw" pivot of the craft. CLA = the geometric center of the lateral plane). The seat is located slightly aft of the center, providing controllability without being overly dependent on the rudder (mildly understeering in automotive terms). There is not much rocker, which improves tracking. The kayak deck with cockpit rim for the paddler’s spraydeck keeps water out, allowing for a lower and less wind sensitive profile. For the same reason, the freeboard amidships can be lower, to allow a lower and less tiring paddle stroke on touring.

Sea Racer and Spindrift – lines

In the surfski, the CLA is moved forward to balance the large rudder. The seat position slightly forward of the LCB is the key to the efficient and precise steering on wavefronts – in automotive terms the ski is slightly oversteered at low speeds, but steering becomes neutral at higher speeds since the longitudinal position of the hull's center of turning is related to speed.

Sea Racer and Spindrift – lines

Note that the Sea Racer is not a typical sea kayak – it was influenced by surfskis from the start.

The station's sections show that the surfski is wider and higher than a kayak like Sea Racer. But the difference in volume and load capacity is not as large as it might seem – the higher Cp of the Sea Racer means that the volume is more evenly distributed along the hull while the surfski has more volume concentrated amidships. This suggests that the Sea Racer-type kayak should be slightly faster on flat water, but the surfski should win in waves.

Sea Racer and Spindrift – stations

The shapes of the sections look quite different. In the Sea Racer, I wanted to optimize the initial stability in what is a very narrow craft (43 cm), with the chines also enhancing steering control when the hull is leaned (a way to keep rudder turbulence to a minimum). For the wider surfski, I chose to minimize friction with elliptical sections below the waterline.

Software and the design process

The sectional shape is also to a degree influenced by different calculation algorithms. The Sea Racer was developed using Bearboat software by Robert Livingstone for the hydrodynamic calculations. The main advantage of this is that the underbody-defining vectors hang from the waterline and the keel, which makes it possible for the software to minimize the wetted surface for every set of design parameters chosen. It saves a lot of time fine-tuning the hull to low friction, but it also means that the bottom and freeboard are two independent sets of curves, meeting at the waterline. On certain kinds of hulls, this complicates getting a smooth natural curve from the sheer to the keel.

For the surfski, I used Ross Leidy's KayakFoundry software, forked from Bearboat, but with one important difference: the vectors hang from the sheer and the keel. That allows better overall control of the lines (including the shape of the deck, stem, and stern) compared to Bearboat. The disadvantage is that you have to work out the wetted surface manually, based on experience, with repeated calculations and checking. For me, a further disadvantage is that KayakFoundry is Windows-only software. I have to run it virtualized in Parallels on my iMac. It works but is a bit slower than Mac applications.

Both Bearboat and Kayak Foundry are easy to use and do an excellent job at their level, but the downside of their simplicity is their many limitations (these are not a problem for the amateur builder, who would solve those issues in the construction phase rather than on the computer anyway). Therefore, I use them for quick zooming in on the hull shape I want, along with all the hydrodynamic data I need – getting within 95% of the final design in a surprisingly short time and with adequate accuracy. From there, I transfer the lines to Illustrator for the final manual fine-tuning, including both functional tweaking and the visual layout of lines and surfaces – which normally takes more time than the first 95% in the design software!

That may seem a tedious way to design a kayak, but the alternative – professional ship CAD design systems are very expensive and bloated with features of which I would use a small percentage (I do not need to know what happens to the ship's stability when 600 tons of crude oil sloshes around in a half-empty tank, nor at which parameters the risk of propeller cavitation becomes an issue ;-) and would take hundreds of hours training for me to master.


The surfski is named Spray – seemed a good name for a younger sibling to Spindrift.

Surfski history

Surfski history appears not to have been written yet, at least in a way that most can agree upon. The following is what I have found here and there on the internet. The history seems linked with surfboards rather than with kayaks. One common starting point is two brothers in Australia, Harry and Jack McLaren, who were using a kind of paddleboard a hundred years ago in the breakers around the family-owned oyster beds at Port Macquarie, New South Wales. From the contemporary descriptions, though called surfskis, these were the real ancestors of today’s surfboards and SUPs rather than the modern surfski.

Sometime in the middle of the 20th century, the rescue organizations in Australia realized that these 'surfskis' were more efficient than the 5-man rowboats that were used to save swimmers swept out to sea by the currents. They were simpler, cheaper and faster, and 1946 'surfskis' were officially accepted as rescue craft – though they were flat surfboards, far from the surfskis of today.

What now is known as surfskis, were developed in competitions between rescue teams from different beaches during the 1950s. The early paddleboards were heavy skin-on-frame designs, but they soon evolved to longer and narrower hulls – still paddled standing up as SUP:s.

At the Melbourne Olympics 1956, athletes from other countries saw the surfboards and were impressed – and the surfski paddlers discovered the efficiency and power when sitting down with a kayak paddle. In the US and South Africa, the next steps in the development of the modern surfski were taken.

In South Africa, the skin-on-frame evolved into foam-filled fiberglass hulls with a cockpit and the main focus was distance competition. In Australia, the sport came to focus on sprint racing in strictly regulated fiberglass surfskis.

In Hawaii, this evolution took off a little later and, very interestingly, without any rules regarding the hulls. The Hawaiian environment was the toughest possible: formidable Pacific swell and fast-moving currents around and between the islands. The Molokai Race became the most important event to evaluate new designs and ideas. It’s very interesting that the record time for the Molokai Race was set by Dean Gardiner in 1997, using an older, shorter, and heavier Hawaiian ski and a standard flat paddle. That’s just one indication that today’s 6.5m surfskis may be longer than necessary. These longer hulls may have been developed to suit a few big, strong competitors who dominated surfski racing, and who could drive the longer hulls to higher speeds in spite of the increased friction from the larger wetted area. But, are these longer hulls the best for us?

I believe that the top surfskis of tomorrow will be perhaps 5% shorter.


Well, Björn, when you say you are going to do something, YOU DO IT!

I wasn't looking for the design to be done so soon. I am greatly encouraged by what I see. It is a seriously good fit for my expected use.

Now I will rearrange some plans and rethink priority.

Hi Rick, yes there was a lot of interest in the shorter surfski, after my intial mentioning of it at the presentation of Spindrift, so I had to rearrange my own plans slightly ;-)

I have already shipped five Spray plans!

But still a lot of other work waiting so I did not have the time to write a full presentation for the Spray page. That will come – but I will not stick my neck out by saying when ;-)


Har lagt upp bilder på mitt Spraybygge på min facebooksida.

MVH Eric

Skall bli trevligt att följa...

Hi Bjorn, thrilled to have come across your Spindrift & Spray designs, as I've been looking for plans to build a "surfski" to be used for fishing along Australian East Coast. I am from South Africa, but been living in Aust for last 12 years and reason I mention this is that I want to know if the cockpit layout of above kayaks van be altered along the lines of the South African fishing surfskis such Stealth, Kaskasi & Pinnacle, with a large centre hatch with foot positioned on either side. I do not mind adding a bit of width if required to achieve this and maybe gain a little bit more primary stability, without losing any of its surf or other caractiristics, which makes it so good. Any input would be greatly appreciated.


Hi Willem, the plans show a generic cockpit that suits most paddlers, but more importantly can be a starting-point for your own version, fashioned to your wishes and specs. My surfskis are intended for efficient paddling, not fishing – so following the plans does not leave much room for a large centre hatch (at least not a wide one).

The loa is easily altered by changing the c/c distance between molds, but widening the hull is a bit tricky. Normally it requires a redrawing of the station drawing. The easy way is to use a photo-copier where the scale can be adjusted individually on width and height. The precision is often not very good for that kind of adjustment, but since a fair hull is achieved by sanding it is a minor inconvenience.

More beam will cost you a little top speed, and depending on your weight, may lift the hull slightly and expose more freeboard to the wind, while impairing the directional stability (but a good rudder can hide such potential problems quite efficiently).

Major changes like that of course relieves me of responsibility for the performance of the surfski – but kayak design is not rocket science ;-)

Hi Bjorn, thanks for the quick reply. If I buy your plan, can I then input the data in the kayakfoundry program and alter it that way to suit my needs, keeping in mind I know nothing of either and would have to learn from scratch, but is more than happy to. All I would want to do was make it slightly wider in the cockpit area so I can fit a hatch between my legs of about 15-20cm wide. Your advice would be greatly appreciated. Willem

Hi Bjorn, this kayak looks really cool and thank you for designing a surf ski in strip plank! I hope to build either a Spray or BP as a winter project, both are very appealing for obvious reasons. I do have a question about the Spray and how it feels before building, we recently had a few hours with an Epic v8 and enjoyed it very much. I am a good paddler of 6' and my wife is a beginner and 5'3", we found both of us could use the Epic and it was not too tippy for her, I found it great fun and easy to be in. Have you ever tried a v8 and could you describe the nature of the Spray with regards to it? Look forward to hearing back.

Luke and Karen. Isle of Arran.

I have not had the opportunity to try the V8, but a qualified guess from the dimensions is that Spray is faster and tippier than V8 and genarally more challenging. But I do not think that is worth worrying about.


1. initial stability is an advantage for beginners on flat water. In waves a lower initial stability results in calmer, more predictable movements and a drier ride, and secondary stability becomes the important quality. This is because stability is the force that keeps the hull aligned with the surface, and thus a disadvantage when the surface is not horisontal.

2. your wife will experience a much more stable craft than you, since the metacentric height is considerable lower (she is shorter and women have the center of gravity lower in the body)

3. even the most tippy kayak is more stable than a bike – stability is mainly a mental issue

4. you are a beginner for a comparably short time – after that you will appreciate a more challenging craft.

I have seen it over and over: kayaks that I have thought of as suitable for competent paddlers have been built by beginners, and the launching report has almost always been that it was much easier to handle than they had been led to believe.

So the important factor is not the properties of the kayak, but your determination. As in most activities: is it important you will find a way, if not you will find an excuse...

Hello again Bjorn,

I have started to look at what timber is available to us and find that Western Red delivered to where we live is very expensive, but I would still like to make a Spray as light as possible. I have used epoxy cloth lots and can be good with the quantities but wonder what timbers you would recommend that we can find locally. General building pine is available in Scots Pine or Sitka Spruce, red and white Pine as its called here. Some of the Sitka can be very light when dry but is a bit prone to not being straight when cut, the red pine is denser and can have resin in it.

Other woods are hard to get in any quantities although there is Meranti building timber that can be quite light and very straight grained.

What should I be looking for ideally? Can we use a foam core?

Luke & Karen.

Normally a light kayak would be built in WRC in USA/Canada and in Norwegian Fir in northern Europe. For a very light kayak I believe Paulownia is hard to beat, but also hard to find depending on where you live. I have no experience of the other species you mention, but just looking at numbers I would suggest that Meranti and Scots Pine (as most pines) are a bit heavy. Meranti is a type of Mahogany – a vast family that ranges from superlight Balsa to very dense Honduran and Sapeli, and there are several species; White Meranti/Lauan, Okoume etc that on paper seem suitable – but, again, I have no experience.

I would prefer a light Sitka, accepting the trouble of non-straight strips.

Hello, Bjorn!

I would like to made this kayak according your plan. But before buying the plan, I would like to ask you some questions. What type of wood you use for kayak? Is cockpit size depend on the size of rower? I'm not exactly understand how to made cockpit and what kind of material is used for it (carbon or wood)? Is the plan of kayak includes the plan of cockpit? How I can pay the plan and how you send it ( by email or post office)?

Thank you in advance for your reply.

Best regards, Valentin.

Russia, Vladivostok.

Hi Bjorn,

can you give me an estimate on how much WRC( cove and bead ) in meters i need to complete the project.

I suppose a working length of 20mm will suffise . I dont see a lot of intricate radii that would ask for a shorter working lenght .

Maybe you can give me the total volume of the Spray and i will do the math myself .

I guess a 370 meters will do but when i calculate a litlle different i get a total of 440meters : quite a substantial difference .

kind regards ,


Robby, my experience, using 5x20 mm strips, is that 360-370 meter strip will be sufficient for the hull and deck (including a small margin for errors). Allowing for bead and cove, make it approx 380 meter.

If you plan to strip the cockpit as well you'll need something like 400 meter – but most builders laminate the cockpit in glass and carbon fibre.

The volume is 334 litre, if you want to do a more specified calculation.

Hello Björn

I am interested in the Spray surfski but I fear that I could screw up the cocpit. Is there a chance to buy the premade cockpit as well as the plans for the boat?

No, I am not aware of any prefabricated surfski-cockpit. You can buy prefabricated carbon rims, seats and hatch trays etc for kayaks but DIY surfskis are too new yet.

But cockpits doesn't necessarily have to be complicated nor involve risks of screwing up. This is what I note on the plans (among a lot of other surfski-related info):


The cockpit shown is a standard cockpit that fits most paddlers – long enough for tall paddlers, plus a sliding pedal set-up, similar to the ones used on commercial surfskis.

When changing the cockpit configuration to fit, remember that the position of the bucket seat is crucial to the performance of the craft – you adjust the forward bulkhead and footwell to your own length while keeping the aft parts unchanged.

The cockpit can be built in many ways: it can be stripped like the hull and deck, keeping the overall shape and volume approximately as on the plan.

It kan be built from foam insulating boards between two solid wood bulkheads, again keeping the overall shape and volume (glue 4” foam boards together vertically to fill the cockpit and cut and sand to shape). This is an adaptive process, where you can work the shape in incremental steps by cutting, sanding and filling, until the cockpit is comfortable and efficient.

An even better way (light and beautiful if executed with care) is to use the foam cockpit as a mold for a glassfiber/carbon cockpit structure. Cover the mold in packing tape and release wax, laminate the entire structure – 4-5 layers fiberglass, 1 layer carbon and on top 1 layer fiberglass (to protect the carbon when sanding). Remove the structure from the mold and glue it in the deck cutout."

Hallo Björn !

I´am somewhat undecided between the Spray and the Spindrift. I plan to paddle mostly in windy and choppy conditions with short wave periods.

At the moment i´am leaning more to the shorter Spray.

My main questions are:

Can the Spray be build with a under-the-hull rudder, like the Spindrift ?

Any suggestions on the cockpit drainage ?

Kind regards


Arndt, both rudder options are indicated on the plans for both surfskis.

The easiest way to drain the cockpit is with a standard dinghy bailer (fx Super Shute or Anderson Mini Bailer). There is an improved surfski bailer version designed by Swedish designer Magnus deBrito, but as far as I know this is not commercially available yet.

Good Morning Bjorn

I am in the mist of the assembly of my strip built Surfski and am looking for the best way to assemble the Hull, Deck, and seat. I made a plaster mold of a Production Surfski seat and will make a layup of the seat in the next week or so. I have the hull and deck all stripped and glassed. My dilemma is with the assembly process for the 3 basic components. I can glass the hull and deck together first then insert the seat and glass the outside and the front and back areas inside where I have some access through the hatches. The second option would be to fit the deck and seat together glass both inner and outer, then try to fit and glass the hull to the desk and seat. The second option would not allow me to completely glass the hull and deck seam as I would lose a good portion of my access. I’m not entirely sure of witch area needs the greatest reinforcement and would hope you could share your insight

Thank You,


I prefer to join the seat pod and deck first since that will be the most critical bond. The hull-deck joint is of course also important, but with a solid epoxy filling between the two parts, double overlapping glass tapes on the outside and as much as can be reached on the inside, it will be more than strong enough.


Thank you for the response on this build sequence. I have been turning this over and over in my head and just I just haven't been able to make the move one way or the other. I will fit the seat pod to the deck first and do what I can to get as much glass tape on the hull inner when I join the hull to the deck.


Hi Bjorn,

I bought a Spindrift plan set a few years ago and have only recently cut the forms with a drive to build. I am an inexperienced paddler so wanted to know the advantages for me of the Spray over Spindrift. Or even if I can adapt the Spindrift to a amore stable aspect?

Also, is it essential to reduce the forms by the thickness of the chosen strip? I guess it'll only be 2-3 hours of standing at the sanding belt.....

Thank you for developing these by the way!


Tom, Spray has a stability curve similar to a performance sea kayak, Spindrift slightly less. But since stability is a perceived quality that is a mental issue as much as a kayak quality it is very hard to make recommendations for someone else.

Stability depends mostly on beam, seat height and center of gravity (meaning that the paddler's length and weight is negative for the stability), but hull lengths is also a contributing factor in favor of stability. Thus, these long surfskis are not as tippy as they might appear from the width figure alone.

To get the proper hull shape you should cut the molds back to the inner contour size (easiest done by drawing a saw line with a marking gauge set to 5 mm). But you might use the molds as they are, thereby gaining a little stability. You might also compensate by shortening the hull slightly (by decreasing all horizontal measurements proportionally, fx 2-3% or something like that) – unless you are heavier than say, 90 kg.

Using the outer hull lines as molds, will, of course, affect the overall shape, so you may need to keep an eye on the lines as you add strips to the hull, and perhaps spend an extra hour on fairing before laminating.

You may also, if you prefer and have the time (mail between Australia and Sweden is not exactly quick), return the plans to me in exchange for a set of plans for Spray. If so, I will charge just the cost of printing and shipping (approx 22 AUD).


Spray jämfört med NK Squall+ som jag tidigare haft och varit mycket nöjd med, men sålt....

Paddlar en intermediate ski (Carbonology Zest). Söker "stormbåt". Vill även ha lucka för tältövernattning, men inte långtur. Tittar därför på Spray.

Tror att du är insatt i båda båtarnas konstruktion. Är det liknande konstruktion? Vad skiljer? Skrovform? Rocker? Paddlarvikt? Fart och stabilitet är ju alltid en individuell fråga i olika förhållanden, men det finns ju siffror bakom. Gissar ändå att spray är en gnutta stadigare.

Jag har inte paddlat Squall+ så det blir lite gissande. Jag tror att skillnaden i initialstabilitet är försumbar, och att några millimeter högre eller lägre sits betyder mer än de små skillnaderna i mått och spantform. Squall+ bör genom sin längd vara en liten aning snabbare, men fart i praktiken sitter ju mer i paddlaren än i skroven.

Spray har en aning mindre tydlig swedform, vilket kan vara en fördel (lugnare rörelser i vågor) eller en nackdel (aningen lägre toppfart). Rocker är ganska lika, men Spray har på konstruktionsvattenlinjen aningen djupare akter men grundare stäv, vilket även det kan vara en fördel (aningen mer kursstabilitet) eller en nackdel (aningen mindre manlöverbarhet) – och framför allt kan det ändras helt med lite packning.

Några exakta jämförelsesiffror har jag inte eftersom mitt ursprungliga ritningsunderlag inte har med de uppdateringar som gjorts på skrovformen.

Tack för en initierad bedömning.

Funderar vidare. Stabilitets och fartmässigt verkar den lämplig för mig. Söker en stabil och surfvillig ski. Har blivit bortskämd med väl-surfande och lekfulla surfskis. Vill gärna bygga.

Good day, very nice design. do your Spray plans also include an option to build it with a kayak deck instead of a surfski? Thanks.

No, Spray is a dedicated surfski, without any other options than a couple of ideas for the cockpit construction. But a few builders have converted Spray to surfski-kayaks, among them Dan Caouette.

But Panthera is just that: a surfski hull, similar to the Spray hull but with a kayak deck. The differences are that Panthera doesn't need that high stem, necessitated by the open cockpit, and is therefore slightly less affected by winds, and the 2 cm more beam makes Panthera slightly more initially stable.

Hi Bjorn,

thanks for that info. Panthera also looks very nice.

Do you think Spray and Panthera would be comparable for speed and maneuverability?

I’m interested in a kayak for long-distance racing on lakes and rivers (100km+). I’m about 178cm tall, 105kg, size 11 feet, and would be carrying a small daypack. I was originally looking at Najad or Norton designs, but am drawn to the style of Spray/Panthera.

Thks, Pete.

Spray has a minute edge on speed in general, while maneuverability is the same (providing they are fitted with the same rudder system). Since the "engine" is much more responsible for the speed made good than the hull, this is not an important difference.

Agreed on the engine importance!

I won’t ask you endless questions, but I do have another please. Panthera seems like a good fit for me. But can you please comment on the suitability of Njord versus Panthera for lake/river racing? The more I read about Njord, the more it also seems suited to the task. But I am unsure how it would do for speed over longer distances.

No problem. I like kayak related discussions ;-)

Panthera and Njord are similar in general speed potential but have different speed profiles. Panthera is the clear winner in theory, on flat water and in waves – 8/12,4 km/h vs Njord 7,8/ 12,3 km/h. (the first figure is efficient but relaxed touring pace, the second is top speed).

But Njord is an odd dark horse! It is highly efficient in a non-obvious and quite surprising way. When you after a day of relaxed paddling look at the distance and time, you realize that the speed has been considerably higher than anticipated. Too many miles in too few hours and you are not even tired and don't know how it happened!

There is a kind of understated efficiency that I can't really account for and wasn't quite prepared for – though I know Njord moves smoothly and predictably in steep waves in a non-tiring way which lets you keep going in your preferred rhythm through whatever conditions and without any interrupting braces, and I know that these qualities mean that your strength will last longer than in a more "willful" kayak.

So if you were to compete in open sea conditions I might recommend Njord, but for lake/river racing I think Panthera's higher theoretical speed will give you an advantage.

Another consideration is that Njord is designed for an adjustable skeg and will not behave as designed with a rudder - for this reason alone it is not on any racing paddler's shortlist.

Sounds like I probably need both, eventually :)

Would narrowing Panthera’s beam slightly make any meaningful increase in speed, without messing up stability? Or perhaps increasing length. I wouldn’t want to decrease load capacity much since I’m at approx 105kg before any gear is considered.

Both less beam and more length will increase top speed. More length will have the disadvantage of needing more muscle power to make use of the speed potential, while less beam will reduce the load capacity (and of course the initial stability, but than I wouldn't lose any sleep over).

As a guide (not quite technically correct), the speed gain from less beam is approx linear and that from more length corresponds to the square root of the length – which means that narrowing the hull is more efficient from a speed point of view.

Perhaps a little of both? Adjusting length is very easy (just increase the station mold distance), while slimming the hull is trickier (you can slim the hull in a good quality copier and adjust the minor errors while sanding).

Or, if you accept a little extra fee, I can provide an adjusted plans set with your chosen LOA and BOA (same price as an individually adjusted Black Pearl: €150, instead of the normal Spray price of €102)

hi Bjorn,

i like the idea of adjusted Panthera plans. what do you think about a 47cm waterline beam, and an increase in length of no more than 12cm? would that preserve a load capacity of 120kg+?

it also looks in some pictures that the sides of Panthera just in front of the cockpit are angled to allow close strokes, is that true?

i may not have been clear, but by 'both' i meant i would ultimately need (want?!) a Njord as well...!



Also, do you recommend 3/16” cedar strips for Panthera?



Yes, 572 cm LOA (44 cm mold distance) and 50 cm width (BWL 47) will be approx 120 kg load capacity and a faster hull than the standard.

There is no traditional cutout for paddling, but with the pronounced dip in the sheer, the effect will be approx the same.

I did get the meaning of a Njord on the wishlist and thought – YES! My sneaky marketing works ;-)

3/16" cedar strip will be strong enough, but you will need to be careful with the strip line-up since the mold distance is somewhat large for the thin strips and with less margin for sanding. 1/4" combined with harder sanding may be a better bet. Cedar is slightly more brittle than the Norwegian fir we often use in Scandinavia (and which I would have used in 3/16"), but also slightly lighter.

Bjorn, turns out i'm in Copenhagen for work last minute from Canada. very unfamiliar with the area, leaving Fri morn with little chance to get out of the city in the meantime. is it feasible to get a set of stock Panthera plans from you while i'm here?? can communicate over email or cell if that's better. Pete.

Pete, I have a set of Panthera plans ready, but you have to come and get them – I have a full workload for the coming days with non-negotiable deadlines.

If you can find the time, there is a train (Öresundstågen) from Copenhagen (fx the airport) to Lund, leaving every 10-15 minutes and takes 30 minutes. I can meet you at the train station to hand over the plans or we can have a cup of coffee and a short chat at my place if you have the time. You can contact me on +46721979390

There are of course courier services, but they are almost as expensive as the plans ;-)

I ran out of time. missed opportunity. how much is shipping to Canada?

Yes, it was a pity – it is always nice to meet builders in person.

The price on the site is the total, including shipping.

Hi Bjorn

I've just purchased a set of Spray plans. I've studied your English instructions and also reviewed Roberto's pages, however none describe the rudder control installation. Also Roberto installs a sealed bulkhead but is not clear if this is in front or behind the cockpit.

Do you your plans show how to instal the rudder and control lines? I prefer the internal rudder but could be persuaded to use an external end mounted version if its much easier.


Hi John, I have not detailed the rudder installation since a look into a commercial ski will show a good and reliable solution – no reason to reinvent the wheel. But the position and suggested installation are indicated on the plans, as are the general shape of the cockpit pod.

There is no need for bulkheads in a surfski since the cockpit pod is tightly fitted into the hull, creating a watertight volume and stabilizing the midship section. This is also shown on the plans.

The choice between an under-the-hull rudder and an aft-hung touring rudder depends on your intended usage: under-the-hull is the more efficient of the two, and if you focus on speed, racing and avoid shallow waters this would be your best choice. The touring rudder (fx Smarttrack) is easier to use when launching or landing from beaches, or paddling shallow waters, where a fixed rudder would risk being damaged.

(Conversation moved from kid's kayaks page!)

Hallo Björn,

mein nächstes Winterprojekt soll eine Marathon Kajak sein. Bin 180 cm groß und wiege 92 kg. Auf deiner Seite gefällt mir der Spray sehr gut. Ist das Kajak für meine Zwecke geeignet? Über eine Rückantwort bin ich dir sehr dankbar.

liebe grüße

Andreas Ahrens-Sander

Hello Björn,

My next winter project will be a marathon kayak. I am 180 cm tall and weigh 92 kg. On your site I like the spray very well. Is the kayak suitable for my purposes? I am very grateful to you for a reply.

best regards

Andreas Ahrens-Sander

Hallo Andreas

Spray oder Spindrift eignen sich hervorragend als Marathon-Kajak für dich. Spindrift ist schneller aber auch mit weniger Anfangsstabilität.

Hej Björn.

Måste bara säga. Vilken kille du är! Vilken kunskap och hur grymt du delar med dig av den. Kan kolla i timmar(nästan) på allt du lägger ut här på sidan. Går i tankarna att bygga en spray eller en spindrift.

Har några frågor bara.

1. Där man bygger sin surfski behöver det vara varmt? Alltså kan man göra det i ett kall garage under vintern?

2. Sittbrunnen i en spray, finns det med ritningar på dem med?

3. Svår fråga å svara på. Men hur många timmar skulle du tro att det tar att bygga en? Är snickare. Kanske kan det göra att det går lite fortare?

4. Finns det ritningar på någon paddel med till surfskin?

Och igen, en grym hemsida. Men en massa godis o kolla på

Tusen tack för svar


1. Epoxyn kräver någorlunda temperatur för att härda till full styrka. Men ner till 14-15 grader är helt OK (men epoxyn hinner inte härda färdigt över natten så det kan bli lite förskjutningar i byggprocessen). Egentligen härdar epoxy så fort det är plusgrader, men dels blir hållfastheten dålig och dels tar det veckor att härda vilket gör det svårt att få någon kontinuitet i bygget.

Bygger du med min metod ribba torrt och limma i efterhand kan du klara det mesta av bygget i lägre temperaturer och bra brassa på med lite värme just vid epoxymomenten.

2. Det finns med en grundritning på formen och tips på olika sätt att bygga den, men inte en steg-för-steg byggmanual.

3. De flesta hamnar någonstans mellan 120 och 180 timmar – med extremer både upp och ner.

4. Till en surfski hör en bra vingpaddel, men det finns inga ritningar för sådana. Men du kan såklart paddla surfski med både grönlandspaddel och europaddel (och det finns ritningar till båda på min downloadsida.)

Hej Björn

Jag samlar mod inför mitt kajakbygge, jag velar en hel del mellan både byggmetoder (strip & SG) men även mellan kajakmodeller. Var fram tills nu helt säker på att jag skall bygg en Frej med SG. Men jag gillar inte kantigheten som SG innebär och jag gillar enkelheten som en Surfski ger. Jag kommer förmodligen pabbla mest i mindre vattendrag och åar, inte på större vatten än Mälaren och Hjälmaren, så själva sufringen blir det nog inte mycket av. Oftast bara kvällsturen och det kan bli en del lyft förbi dammar etc, att då slippa kapellet känns som en fördel.

Nu till frågan: Mina förvaringsmöjligheter är i garaget som är 550cm långt, fungerar det bra att korta ned Spray till ca 530cm?

De flesta Surfski är betydligt längre och det måste bero på något, blir det en för tuff kompromiss att korta ned spray till nästan metern kortare än övriga Surfski? Jag är 175cm och väger 70kg.

Surfski är generellt långa för att mycket av utvecklingen har skett på tävlingar i öppet hav och de dominerades tidigt av några stora starka hulkar som som kunde dra nytta av längder upp mot 6,5 meter. Men en kort surfski fungerar lika bra som en kort havskajak (även om man inte vinner Molokai Challenge i en sådan).

Lastkapaciiteten varierar linjärt med längden (5% kortare skrov ger 5% lägre lastkapacitet) så du kan enkelt räkna ut att den räcker till för dina behov.

5% lägre lastkapacitet kan jag leva med.

Nästa fundering och det är lite pinsamt för jag tror jag sett svaret på din site men jag kan inte hitta det igen.

Om vi förutsätter paddling på platt vatten. Hur skulle en surfski som spray med justerbar skedda betesig jämförbart med manöverbara havskajaker som Frej?

Jag föreställer mig att justerbar skedda är enklare att bygga eftersom det är ett enklare system än roder, det väger mindre och lite billigare.

Det är möjligen aningen lättare att bygga en skädda än ett roder, men köper du färdiga delar är skillnaden marginell.

Spray och Frej liknar varandra genom att de har krökt köllinje och är mycket (för att inte säga extremt) manövrerbara. De skiljer sig genom att Frej är konfigurerad med viss kursstabilitet vilket Spray i stort sett saknar. En bil-analogi skulle kunna vara att Frej har nysningssäker familjebilsstyrning medan Spray har en direkt formel-1-styrning. Frej är alltså lite mer laidback i karaktären och Spray lite mer "på", vilket i kombination med ett högeffektivt roder ger spetsegenskaper vid surf i grov sjö och därmed möjlighet att med hjälp av surfen nå högre fart.

En annan analogi är generation-5-jaktplan som får fantastiska flygegenskaper genom att man tagit bort planets naturliga stabilitet i luften och istället tvångsstyr planet genom ständig datorstyrd roderpåverkan.

Med en skädda nerfälld skulle Spray bli tämligen lik Frej i känsla och manöverering – men drar du upp skäddan helt kommr du att märka att den saknar kursstabilitet.

Hi Björn!

As a tall guy I have issues in fitting into kayaks like Viper. At 195cm and 98kg I haven't really felt confortable in any faster boat I have tried. Plus, there has been a lot of swimming as getting back in is pretty hard due to water in the boat and few other issues.

So I started looking into surfskis as they are easier to mount after my frequent splashes :) but as I am inlands and only paddling on lakes so far, I am interested mainly getting flatwater speed. Pantera combines surfski with kayak cockpit, but have you ever considered designing it the otherway around - i.e. straight going hull with a surfski cockpit? Any sense in such idea, or does a proper ski just make more sense?

Anyhow, Spray looks like a really attractive project. Would you consider the std beam width version adequate for a 100kg paddler or should it be lenghtened, or the wider one?

Thanks in advanvce and br, Janne

Hi Janne

I have very little experience of and in flat water racers, since I spent almost all my paddling years touring at sea – thus the focus in my catalog on speed, maneuverability and sea-keeping ability in wind, waves and difficult conditions.

But I think that the difference is smaller nowadays. Flat-water racers have over the years got more rocker, since it was discovered that rocker was the least detrimental way to accomodate heavier paddlers – and surfskis have recently done exceptionally well on flat water (outrunning Olympic racers on long-distance races on lakes and rivers).

So I think you might do well with either a Spray, or even better a Spindrift. One prominent advantage of rocker is that the paddler sits lower in the hull and thus get a lower CG, that together with more length increases stability significantly. Therefore you can accept less beam in a surfski than in a racer and have a better stability, both initial and secondary.

I think you can use Spray or Spindrift as they are – Spray is intended to also be used as a touring ski, which means a little extra load capacity, and Spindrift have more internal volume than Spray. Also, since an open surfski is intended for use in big waves the given figure for load capacity is generally lower than for a comparable decked sea kayak - meaning that on flat water the load capacity is larger than the quoted figure.

If you want to change one dimension the LOA is the "cheapest" way to increase stability – increased beam slows the craft down more.

Hej Björn, det råkar inte vara så att du har en ritning på en dubbelski typ spray?



Hej Per

Jag har i datorn en Spindrifttvåa som borde varit färdig för länge sedan – men angelägna uppgifter, både privat och på jobbet, har stökat till planeringen en del (det är hårt jobb att vara pensionär ;-)

Finns intresse kanske det kommer en Spraytvåa också – men det kommer att dröja. Jag har fler todo-projekt på agendan och i datorn innan jag hinner dit.

Hej Björn!

Angående deplacementet på 110 kg:

Om vi ponerar att båten blir 20 kg tung och jag väger 85 kg.. Då blir det bara 5 kg kvar som jag kan lasta? Eller tänker jag fel?


Nej, du tänker helt rätt. Men surfskis är lite speciella eftersom de har öppen sittbrunn. Vatten på däck är inget stort problem med en täckt sittbrunn, men lite vanskligare med en öppen. Hade Spray haft däck och kapell hade jag satt lastkapaciteten till 130-135 kg. Skillnaden innebär ca 2 cm större djupgående.

För en rimligt stark paddlare som håller fart på kajaken suger länsen ganska snabbt ut det vatten som kan skvätta in i sittbrunnen, men för en som paddlar långsamt kan det ta lite tid. Eftersom jag inte vet vem som kommer att paddlar surfskin har jag varit försiktigt med utfästelserna.

När jag får inte lite fler rapporter om och erfarenheter av Spray i olika situationer, kan jag förmodligen öka lastkapaciteten i tabellen.

Jag förstår, tack för utförligt svar!

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