Project 6'6'', 56l Volume, Single Fin

Hello guys, in addition to MiWi’s post, I would like you to discuss the upcoming project of mine.

The restrictions are: 55 year old, landlocked, surfer, with more than ten years, vacation only, surfing experience, meaning average less than 2 weeks a year. Level not more than late beginner/early intermediate, able to catch green waves. Prefered wave: slow breaking, chest high, max. head high.

I definitely need some volume to paddle and to catch waves, but I prefer short over length.

My draft shows a rather wide front with a narrowing tail, Bottom a definite Vee from mid to tail, front flat. rounded rails, getting sharper into the tail. single fin… Idea is to get a forgiving board, which helps getting into waves. Should turn good into larger bottom turns. Should hold its line, once set. No aerials, softer turns riding along the shoulder should be possible.


Fell free to share your thoughts!

The board will be build as a hollow wooden construction using balsa; a deck layer of veneer and glass…


It’s doable - it just depends how you want to surf

I built one a couple months back that is 6-10 and came out to 66 liters for a surfer that weighs 260+#.   It floated him easily and he has no problems controlling it.  .  

I built the board for him to travel with it, so with that in mind I stuck to epoxy over PU blank - that way he could deal with a ding by slapping a sticker over it.    And I had to use a finbox system and install that would adequately support a surfer of that stature and a board of those dimensions.   

Building it should not be the problem, the question for me is more, will it be able to surf, how I wanted it to surf (see first post)

The build looks nice, I actually can see some similarities between my blueprint and yours. I do own a Pukas 6’6" with 63l. I like it, its a wave catcher, but due to its width (and volume) its difficult to hold a high line. Thats why I narrowed the tail, removed some volume. But the question is, will it ride like intended?

By the way I’m about 6foot something tall (1,84m) and weigh about 170lbs (82kg)

I think your outline will Be restricted by your abilities. (Just based on my interpretation of your description). 

I would steer you into something more balanced. (based on my limited knowledge of your current boards and what you can/can’t get them to do) 

Personally, I think there’s a point of diminishing returns when it comes to volume vs length.   I tried to talk my surfer into a shorter length with less volume but he normally surfs a longboard and we weren’t sure if he would be comfortable on less than the 6-10.   Volume notwithstanding, I did bring the rails down to aid in hold, and I added a light chine to the bottom fading into some vee to loosen it up relative to the width.  

For someone at your weight I would say that if you can’t get it done on a 6-6 at maybe 45 liters then adding 10 more on top of that isn’t going to help you.   Once you get past the volume it takes to float you I think the amount of surface area you’re working with becomes more important to paddling speed.  I generally look at the two factors as almost being independent of one another.   

The builder behind Sunova (Bert Burger) is a real big guy and the last time I saw him comment on it he said he likes wide widths and thin foils for his boards, like 24" wide x 2" thick and with lots of concave.  

Plus, duckdiving a cork is no fun.  My surfer doesn’t have a problem handling his board or getting it to set a rail, but then again he has 100# on you so he has lots more leverage.   


Just a thought.  

use less tail rocker

narrow the nose or widen the tail or both (wide point forward is OK but that outline is top heavy to an extreme)

This is the Pukas Plus 7.0 with 70l, I own the 6’6’’ Version with 63l…

It is even more voliminous, than the new draft, it catches any wave, but it is quite difficult to hold a high line in the wave. I reduced volume and narrowed the tail, trying to improve the performance of the Pukas. Regarding volume distribution, the most volume is more or less under the chest, between 1/3 and 1/2 length from the board. The volume distribution (given by Boardcad) is similar to the last 70th single fins, maybe it is a little bit more upfront. And if I look at 70th Single Fins, I like the look and how they perform. Of course the board is  wider and higher, but as soon as the Pukas is in motion, it does not feel that corky anymore, I believe, that if riding, the surface and outline is becoming more important.

56l is still a lot, but its already 10% less than the Pukas. As said, it should improve the overall performance of the Pukas. If I ride this one with success, whatever this means, I still can go ahead and build an next on, going below the 50l mark. 

Three things:

 - Singlefins don’t get their drive off the fin cluster because there isn’t one - they get their drive off the rail line.    Your 6-6 length is a little short for that, and your template has a lot of curve behind the wide point.  Curve is for control, but you want straight for drive.  If you added a few inches in length without adding any more width it would make a big difference.  

 - You weigh 170#.   No matter how weak a surfer you are you still have plenty of weight to turn a 15" tail, especially if you have some vee in the bottom.   Add some width back into your tail block - it will increase the surface area in the tail and straighten out the rail line in your template.  

  • as one of the other posters noted, your template is a little too extreme  - move the widepoint back a bit.  3 or 4" forward of center is plenty.  

Honestly, they figured out what works with the short singlefin designs out many years ago.   Go back and look at the designs they were doing in the late 1960s and 1970s before the thrusters came along, especially the Australians.  Use what’s already been proven as your starting point and go from there.  Don’t start with a design that was aimed at kooks and then take that to an extreme.  


Here’s a reference catalog that tracks the older board designs.  Click through and see what other people were doing with the short singlefins, and then take note that the really short singlefin eggs only lasted a few months because people figured out real quickly that they don’t work.   It was putting fins out at the rail that made the short lengths work:



Thank your for this sound evaluation! I will study the given link and see, if I can redesign the board according to your tipps! Since I have not started the build yet, I’m able to make changes.


This is my last build, a 7’6" 4piece collapsible. I was astonished how good it turns, and its holding its line. If I compare this board to your recommendations, I think its close, at least from mid to tail. The front is wider. I forgot to mention, that I ride more from the front foot, due to an accident almost 40 years ago, when I broke my left leg. This is maybe one reason, that I prefer by now a tail, that is giving more hold and control with less leg pressure than usual.

I’d def widen the tail. As an occasional surfer,  You’re going to have wave catching problems with such a narrow tail. More balance in the overall template as noted previously. 

All the best

If you want an extreme front foot friendly design then maybe check out the displacement hulls like what Greg Liddle or Marc Andreini have been doing.  Of the two, the Andreini designs are commonly considered more moderate and versatile while the Liddle designs are usually considered more specialized.


Due to the surface areas involved these types of shapes have plenty of volume and paddling speed for a 170# surfer so long as you don’t try to go too short.  Morevover, adding more thickness won’t improve the paddling speed.  All it will do is make them harder for you to handle.   

Here’s the thing about thickness - if you weighed more you’d need more volume in a given length to get adequate float when compared to someone of lighter weight.  On that 6-10 I did, he probably could have gotten it done on a shorter length or less volume but he hadn’t surfed a midlength or shorter length in 10 years and we wasn’t sure he had the timing right to make the length work for him during the one surf trip.  I barely finished that board and it’s fins on the day before he left so he didn’t even have a chance to try it out in advance.  He had to have a board that he knew would work from him right out of the gate and without any adjustment period.  That’s the main reason we went with the beast.  

Took a look at the boards, liked the Greg Little Death Machine and the GL/PB. Unfortunately there are no dimension, but in general there are more moderate than my draft. Widening the Tail, narrowing the width and putting the highest volume a little bit back should aim in the direction all you guys proposed. If I reduce then the height a little the volume should go between 45 and 50. I think I should give it a try. Some inch longer could be fine to but my availlable balsa planks are 6’6"; meaning more than 6’10 will get difficult, without joining. 

Thanks for the recommendations! 

With respect to length, 6-6 + nose and tail blocks will easily get a few more inches.   At your weight and skill level a 6-10 x 22" x 3" should be real easy to paddle.   

The complete Liddle design is very specialized and technical to build.  And surf.  It’s not for everyone, and in fact relatively few people surf them. 

The transition hulls in general tend to have much lower rockers than normal (Like 1" in the tail and 3.25" in the nose), heavily rolled bottoms, heavily foiled nose and tail decklines and real thin rails.  The Death Machine model you mentioned is a particularly extreme version of that, which is why it’s called that.   You can watch some Youtube videos that show guys surfing those boards (search “liddle hull”).  You’ll see that for the most part those guys are sufing frontside only in conditions that are head high or smaller.  

With all that said, you could take certain elements of the hull design - like the template - and put them on a more moderate rocker and more moderate foil, bottom and rail setup and get a much more versatile design.   At 6-10, a rocker with 4" nose and 2" tail could work into overhead conditions so long as the wave wasn’t pitching.  You could use a simple egg bottom (slight roll in the nose, flat through the center with roll at the rails and a moderate vee in the tail) and a moderate foil (1" in the nose and tail) and that would be real easy to surf.  


With surf design, a little goes a long way.  So if you were having a tough time with inadequate volume on one of your previous boards the solution may be to just add another 10% of length or another 10% of volume.  Adding 40% more volume is going to create more problems than it solves.  Same thing with widths, rocker and bottom contours.  Better to add not-quite-enough than to add too much.  IMO


I made another draft. Resulted in kind of an egg… The bottom is still flat front blending into a vee from mid to tail. Tail Rocker dropped to 2 1/2 form 3x; front remained more or less unchanged. I foot from the tail it widened from 14 1/2 to 15 7/8, front width reduced from 18 3/8 to 17 1/8, Height diminished by 1/4. volume dropped to 50l.

But… the first shape is quite experimental and I like experiments, maybe I will build both, would be really interesting to compare. 

Anyway thanks again for the input!




Hi there -

For a ‘maximum head-high’ wave size I think you could easily go to 16" (or more) in tail width and with the addition of side fins (thruster) still maintain control and hold a high line.  Catching waves will be easier and your overall ride experience will be far more forgiving.  

There are some good reasons why thrusters are still one of the most common fin layouts - since 1980.

Balance that outline and add a couple of side fins… Be happy. 




To be completely honest, I like the 2nd template a lot.   I’ve kept a midlength singlefin with variations on that general shape on hand for probably 20 years  - my current one is 7-10 but they work really well in the 7-0 range and a little shorter as well.   I use these in lieu of a longboard, which is not to say that this length is competitive with a competent longboarder but then again only 20% of the people who ride longboards are competent on them.   So I can usually get my waves even when I’m surfing in a longboard spot. 

Now your next consideration is the curve of your bottom rocker.   Since you’re using Boardcad you can import rocker shots from various profile pics and match their rockers to see how those curves work.  So what I suggest is that you open a new file (not the one you’re working on right now) and use it to study rockers.   You can download a blank catalogue and take screen grabs of some of those rockers and then import those images as your background for the profile - then “map” those rockers to see what measurements those curves produce in the 3" increments.    Then if you want to raise or lower a rocker from there the curve will move with you.  

The template files in boardcad are based on shortboards, funboards and high performance longboards which have way more rocker than the traditional singlefin longboards and midlengths.   Normally what many shapers in the midlength singlefins do to get their rocker is they’ll start with a blank that starts with a relatively low rocker like the 7’4" SP or a 7’9"H and Figure out where on that blank they’re going to put their template to see what the bottom curve looks like at that point.    

Since we’re just talking about doing a separate study on rockers at this point let’s say for the sake of this exercise you wanted to do a 6-10 length on the 7-4"SP blank.   That means you’d probably cut 3" off of both ends.  Well, in doing so with the natural rocker of that blank you’re going to end up with a nose rocker at about 3.25" and a tail at almost 2" - that’s before any additional shaping.    Moving the center of the rocker forward or backward from there will alter those numbers but might also affect how that board surfs.  

Now if you were using a different blank that had more rocker you might order a custom rocker and they’d bend the blank to fit - most blank companies offer that option.   

The point here is that most designs have some curve through the middle even if they are more subtle in the middle and more progressive at the ends - no real flat spots as such.  That’s what you want to be shooting for with your board, especially when you’re not starting off with a manufactured blank.   So this is where spending a couple hours studying rockers and blanks and looking at pix of finished boards to get an idea of what other builders are doing with their boards will save you some hassle later on.   Don’t just look at the one thing you’re trying to do right now - look at a variety of board designs to get an idea of which kinds of curves go with which kinds of boards.  

For the record, at your age and stature I’d still recommend a little more length, like 7-0.  It’ll make a difference in how smoothly and how fast the board will naturally surf.  You can hide a break in your center planks (because the planks to the sides will already be shorter when you cut the template) by putting a separate logo block.   

Some of the midlengths I’ve built.  

@gdaddy A big like for no 1 and 2. Although its a totally different than my first draft, I think I stick to road you plastered. Finally it will be more your shape than mine, but I do see myself more a builder than a shaper. Since I do not surf regularly and have no access to the ocean, I will never dig into the shaping wisdom

Increased length to  7’2’', read the parallel rocker thread of sk8tement and adjusted the lines eyeballing, reduced height to 2 6/8, still got 51l…

The plank length is not a real problem, I will veneer the deck anyway, I just need more wood. I get the balsaplanks premilled at 200cm by 20cm in thicknesses from 2 to 10mm. The total price for the balsa for a board at the given size is somewhere between 100 and 150€.

Lets go ahead:




I haven’t done anything unusual.  The first pic is a board I did almost 20 years ago - it’s a very conventional design.  I did several of these and I still have one that I’ve been using as a test mule for the foils.     #2 is a 2+1 double ender that I built for a friend right after Clark Foam quit and everyone was scrambling to learn epoxy and EPS.   The other three boards are more recent - I’ve been using wide-point back designs for my personal midlengths since 2010 because I prefer how they surf.   You don’t move around as much between putting the board into trim vs turning it.    But those designs aren’t as user-friendly so they aren’t for everyone.  


The board with the veneer has a 1.5# EPS core, 4# PU foam rails and finbox insert, and bamboo veneers.  7-0 x 22 x 2.75"  with a really flat rocker and a semi-hull bottom.   Believe it or not, that board initially came out a little too light for a singlefin (it didn’t have much glide) so I went back and added another layer of glass to get more weight.  That was one of my favorite midlengths, except it was aimed at slow/small conditions.  Not a versatile board at all, but real fun for the narrower range of conditions at which it was aimed.  

The 2 at the bottom are more recent and are longer at 7-8 and 7-10; not because I need the length now but because I am pushing 62 and I will be needing the additional length as I get older.  I can still duck-dive the 7-10, but just barely.   I think I’d actually be more comfortable at maybe a 7-4.   

But that’s my progression.  Your path will be your own.  I think what you’ve got now will be way easier to surf across a wider range of conditions than what you started with.    You’ve got plenty of rail line going, a nice combination of curves.    


One option in Boardcad that you can play around with a bit is toggling on the “show center of mass” and “show volume distribution”.    Then watch how those indicators change when you move wide points, widths, thicknesses and foil around.   If you compare where the center of mass is on your first design vs your latest design it’ll give you a little better idea of what these design elements are doing.   

In the end, there’s no substitute for committing to one design, building it, surfing it for what it is and learning what you did and didn’t like for the next board you make.   The different types of construction are cool and all, but as McDing says, “shape comes first”.