HWS SUP design feedback

Well I’ve been MIA for a long time. Just about finished building my first compsand and am now planning to finally build the SUP and trying my hand at HWS while I have access to a bandsaw.

Going to give Huck’s solid rail frame approach a try, so solid redwood rails with mostly balsa skins (to help reduce weight) and redwood stringers/trim.

please see attached APS/AKU PDF. Could not figure out how to attach the brd file :frowning:

10x22nx29cx20tx3.5 fairly boxy 50/50 rail, with flat deck most of the way to the rail then small bevel down to thin the rail a little.

I’m 6’2", 180lbs + SoCal wetsuit (either 3/2 or 4/3 + booties). It is intended to be surfed not just paddled but will also be used for flat water paddling a little.

Thanks in advance for the input.

Have a Gold Medal Day!

so what do you think of this…

10’ x 22" n x 29"c x 20"t x 4" 

does this sound reasonable for someone 180 lbs wearing either a 3/2 or 4/3 suits (i.e. 180 + wetsuit, booties and paddle)?

see updated APS/AKU PDF

notice the slices… would you leave the bottom rail edge sharp so it is like an all down rail?


Have a Gold Medal Day!



Way too thin. 4" if you like them thin. 4 1/4 better.

50/50 rails reduce stability. You may regret that. Use shortboard rails nose to tail and you’ll be more inline with cutting edge SUPs.

Rocker and scoop are flatish for a SUP. The good ones use more. You get early glide from the width, so if you want it loose, bump the rocker up to high 3s for low 4s.


Hello, oxymoron!!


Thanks for the feedback. I know that most SUPs are in the 4-5" range but it seems unnecessary. 


Based on my weight, 180 lbs, and my water weight calculations (i.e. amount of water displacement needed to support my weight) I come up with ~80 liters. Add some weight for wetsuit and paddle lets call it 200 lbs (with margin) then we’re at ~90 liters of displacement. Add another 30 lbs for the HSW SUP (again more margin) and now we are at ~105 liters. Based on the APS/AKU calculations the board will provide ~130 liters of buoyancy, which would support ~286 pounds.


Is 30+ liters plus the built in weight margin not more than enough? 


My thought was by adding width throughout the board and carried the thickness out towards the rail that I should have plenty of volume even at 3.5 inches. Am I wrong? I figure I might need a little time to get used to it.


One reference I have is I once used an 11’ surftech soft-top numbers: 11’ x 17.6" nose x 25.5" center x 15.9" tail x 4.25" (volume 120 liters)

Though I don’t know if these actually match the board I borrowed as it was about 5 yrs ago. Sure it was a little un stable but with some practice I think it would work fine. Anyways I don’t want a dock as I figure part of the purpose is to get the exercise of standing and balancing on the board.


As for the 50/50 rail… I do have 1 local shop that has a couple SUPs I can go look at, but even with the fairly full boxy rail you think 50/50 will introduce too much instability?

The PDF attached in the 1st post shows the rail shape I have planned.


Thanks for the input.

Have a Gold Medal Day!




Didn’t say cutting edge surfboard. Cutting edge SUP!

I’ve been SUPing since 2007. I’ve suffered through the early SUP designs by shapers who thought they knew what worked based on their 30 to 40 years of shaping prone surfboards. It was misery in the early years. Everyone throwing their better ideas out there and making SUP way harder that it is today. SUPs have advanced so much each year, that something just a year old is really bad compared to the latest. I won’t wish anything shaped two years ago on my worst enemies.

So you can do it the hard way, and do what you think is right based on all your experience with prone surfboards, or you can look at what the cutting edge SUP guys are doing “as a guide” and save yourself tons of grief.

Go down to the beach and check out some cutting edge SUPs from Paddle Surf Hawaii or Naish shapes by Harold Iggy.

Back to your questions. 3 1/2" thick will reduce stability a lot. The rail shape will reduce stability a lot. If the board is not stable enough to stand on for 2 or 3 hours you will be miserable. 

Demo a few before you shape one. You will learn a lot surfing a few good ones first.

It may look simple, but it’s not prone surfing. It’s SUP surfing.

Sorry for the rant. Just trying to “really” help you. 

P.S.  I’ve watched the surfboard factory where I buy my supplies struggle to get it right. The shaper became so frustrated with it, they gave up. I hope this helps you avoid going down the same road.




Thanks for the input. I’ll see if I can find a shop near by that has the ones you mentioned.

So other than thickness and rail shape… does the outline and rocker make sense?


Have a Gold Medal Day!



I measure almost everything I get my hands on. From this chart, you can see the rockers are more than what you’re doing and these boards are shorter than 10 ft. You should be able to extrapolate from these where a 10 ft rocker should be. 

The most common bottom shape today in a SUP for good stability paddling, is dead flat at the middle. It’s critical the bottom not have any vee or be round where you stand paddling, or you’ll have constant nervousness or shimmy in your legs. You can add vee behind where you stand paddling without any ill affect. A 50/50 rail adds some wobble and the farther back you bring the 50/50 the more wobble. Most SUP rails, regardless of size, look more like shortboards. A classic longboard shape with rolled bottom and 50/50 rail is almost un-rideable. So take my comments on rails, look at some good SUPs and refine your rails to suit. The pdf looks more like a rough cut to me at this stage.

A couple more thoughts.

When you check out those SUPs, pay close attention to how they blend the deck into the rail. The flatter you make the deck, the more stable and enjoyable the board will be. But flattening the deck, thickens the rail. It’s tricky to get the rails right and not add too much dome. Dome is bad. Step rails are not the answer either. 

Check the templates. Parallel templates are bad in my opinion. There is one big brand of SUP where all their shapes have very parallel templates to make them paddle straighter. They market this feature. I don’t like the way any of their boards surf. Only a newbie SUPer struggles with the board not paddling straight. An experienced SUPer doesn’t care how it paddles, only how it surfs, so keep the templete curvy.


Do you consider the outline template I have below as curvy enough?

[img_assist|nid=1056673|title=SUP outline 4_4nr v0|desc=SUP 10x22x29x20x4 - 4 1/2 nr - outline|link=none|align=left|width=640|height=239]










What about the deck rail blending… I was planning to do a flat deck then a bevel  down into the rail. I’ll round the top edge of the bevel to blend it into the deck a little more than I have shown in the center slice below. And does the tucked under edge look about right for the center of the board?

[img_assist|nid=1056674|title=SUP 10x22x29x20x4 - 4 1/2 nr v0 slice|desc=SUP 10x22x29x20x4 - 4 1/2 nr - slice|link=none|align=none|width=640|height=98]

Finally rocker… I was not sure if you were saying I needed more or less rocker when I was at 5" of nose rocker. Looking at your chart and rocker pictures of a few SUPs online I dropped the nose rocker a touch to 4 1/2.

[img_assist|nid=1056675|title=SUP 10x22x29x20x4 - 4 1/2 nr v0 rocker|desc=SUP 10x22x29x20x4 - 4 1/2 nr - rocker|link=none|align=none|width=640|height=110]

Thanks again for the input.

Have a Gold Medal Day!


Oops while playing with the design I did not reallize that I had tweaked all my widths and added an inch…

Here is the intended outline: 10 x 22n x 29c x 20t x 4 - 4.5nr v1

[img_assist|nid=1056676|title=SUP 10x22x29x20x4-4.5nr.v1|desc=|link=none|align=none|width=640|height=208]

So does this one have enough curve to it?


Have a Gold Medal Day!


The template looks a little crude yet to me. Take an image of the Naish Mana 10’ from the web and insert that into AKU and overlay.

I’ve never seen a nose that low on any SUPs I’ve measured. I’d do 5 to 5 1/2 on the nose and 3 3/4 to 4 on the tail. What do you want, speed or loose?

Rail at the middle doesn’t look right yet. Check some SUPs. I use that profile tool from Home Depot to copy rails and get me in the ballpark.

I was checking out the Naish website and it seems like the Nalu series might be more inline with what I am after. More wave oriented and less flat water. I also don’t think I need/want all the buoyancy in the Mana series. For example the Mana 10’ is 210 Liters, Mana 9’5" is 190 L vs the Nalu 10’6" at only 153 L and the Nalu 9’6" at 135L.


Any thoughts on the difference between the two? Unfortunately I don’t have any good SUP near by to check out or tryout (1hr from beach and any good shops).


Thanks again for all your advice.

Have a Gold Medal Day!


I’m 6’2 averaging 185 lbs. My ideal longboard style SUP would be 9’6 x 29 wide x 4 1/4.  I’d take that 9’6 Nalu and add 1" of width to get 29"

30" wide would make it easy, and probably best for a new person to standing.

29" would make it better performing without making it too challenging on choppy days (for me).

28 would be hard core performance, but harder work on choppy days (for me) and probably a nightmare for you, but do-able on glassy days for you.



Dwight, Thanks.

Since we are about the same size, what would you consider the ideal nose and tail dimensions for your ideal LB style SUP in the 9’6 x 29 x 4  1/4?

Right now I’m leaning towards 9’6" x 21n x 29c x 17.5t x 4+ inspired from pulling the 9’6" Nalu into APS/AKU.

So it  would be a diamond/pin tail with Vee starting about 2-2.5’ forward of the tail and full concave through the middle of the board.

Should the concave continue up into the nose, belly or go to flat in the front 1/3 or 1/4 of the board?


Have a Gold Medal Day!


That sounds good. I don’t have an opinion on the concave, other than to tell you Naish and PSH do very shallow concaves. Almost flat.

OK, how about this design… Its inspired by the 9’6" Naish Nalu but widened slightly from 28" to 29". 

The rocker is just a modified version of the APS/AKU default 9’ LB rocker. Increased the tail rocker to 4" and the flattened out the middle of the rocker as well.

Please provide feed back. Hoping to start working on the outline template and then Huck’s solid rail system.

Whats not shown here is that I plan to put a slight concave through the middle of the board and Vee coming out the tail.

[img_assist|nid=1056877|title=SUP 9_6 x 20n x 29 x 17_5t x 4 nalu|desc=|link=none|align=none|width=640|height=479]

Have a Gold Medal Day!