Volume in liters for Classic Keel Fin fish

I am interested in getting a Classic Keel Fin Fish (something like the Steve Lis Fish pictured below).

However, I cannot seem to find data on volume in liters for these kind of boards. Does anyone know the

volume in liters for Classic Fishes? I am looking for something in the 40 liter range, so what kind of length

would I need if I am going for one with a width of 21.5"  (under 6’2" if this is possible).



A lot depends on your planshape, how you foil it an how you carry the volume out to the rails and such.

I´ve built myself some fishes and measured the volume.

5’8 x 21 x 2.75 = 35l

5’10 x 21 x 2.8 = 37l

5’10 x 21.5 x 3 = 42l

Thank your for the quick reply. I found an older posts with

dimensions of a Steve Lis 5’5" with special attention to planshape

and rails. https://www.swaylocks.com/groups/55-lis-fish.

The 5’5" Steve Lis Fish dimensions are attached as a PDF

I am neither a math guy or a shaper but if I extrapolate these

measurements for a 40 liter board, what kind of measurements

in terms of length/width would fit?






IMO learning to use Shape3d is very, very handy for getting a sense of volume & what affects it. It’s a free DL here: https://www.shape3d.com/Products/Shape3dLite.aspx

I found it easier to learn to use than AKU Shaper, though others have told me they found AKU easier (no idea why, but Shape3d was more like using a classic graphics program, at least to me, right away).

I still use it for many boards, and when “stubbing out” existing designs to make them shorter/wider/thicker for myself and trying to hit a target volume I’ll let the program make the changes, and then handshape from the numbers I get from the tweaked Shape3d file. Results are usually very good. For some reason, when I actually order Marko with CNC cuts from the Shape3d file, rockers seem to come out a bit weird. That weird Marko result could be my fault, but I use the same numbers and put them in by hand when following the process I just described with consistently better results.

Working with slices will really show you how foil and width and thickness changes affect volume because you get an immediate numerical volume result, onscreen, with every change you make.

Eventually (for me, around board 55 0r 60) you start to get an inherent eye for volume. No doubt for some that could happen sooner or later than in my case.

Funny story about volume (not sure if I’ve related it here before): I know a very established shaper here in town who is very generous with his insight. I ran into him one time when I was making a board for a 100 lb intermediate female rider – HPSB semi-step, based on a 7-9 Pearson twin – and was puzzled with what volume and dims to go with, but I came up with about 22-23L. She asked me for 6-0, I think. I made a file for the original 7-9, shrunk it down to 6-0 and tweaked the dims to hit the volume target. When I saw the expert shaper, I asked him what volume he thought I should try to hit, gave him the rider’s details. He said, “Wellll, I don’t really do volume. What’s the length?”

I told him the length.

“So, what width were you thinking?”

Before I could answer, he shot out a width. It was exactly the same as what I had come up with. I told him so.

“So then what thickness?”

And the same thing happened: he shot out a thickness before I could answer, and it was exactly the same (to a 16th") as the thickness I had gotten via starting with volume in Shape3d.

Using the template, rocker numbers and deck/rail profiles in the book my iteration came out at 35L for the 5-5.    But that’s with the zero rocker in the tail, flat deck, and a fairly clunky foil with the heavy beak nose.    More contemporary versions of the Lis layout go with 1" or more of tail rocker and a slightly more streamlined foil and deck rocker.    

I did a fishie variant a few years back with a little more curve - and at 5.8 x 21.5 x 2.75 that board hit 40L.  I took the middle out of a 5-10 fish blank and that board ended up with 3.5" in the nose and 1.5" in the tail, so that’s fairly flat but not extreme.  



If you want to make a Lis style fish, I took an image I had of his original 4’ 7" fish scaled it up to 5’ 5" then cut it up into 11" x 17" sections. I can’t remember how wide it is but it’s probably between 21" and 22". I made a wood template, but when I measured it, it was only 5’ 3". I also made sections for a 6’ version, but I didn’t print it or make a board.

I do all my shaping by hand and I don’t think about volume. I make boards for myself and they tend to be thicker, between 2.5 and 3".

I’ve included the full outline image and the 6’ sections. It will probably end up with a 5’ 8" or 5’ 9"  template. You need to print it with an 11" x 17" printer. I also included a shot of the board and the block of foam I made it from, a single piece of 3" thick Dow XPS styrofoam. I gave the board to a friend and he loves it.


I do all my shaping by hand, too.  I only use the CAD for design, and so I can figure out which blank/rocker to order and where to place the template on the blank.  

I’ve been making my boards with EPS or XPS, and in most cases I glue pieces of foam together to make a blank. About 10 years ago, I bought 11 pieces of Dow XPS that were 8’ x 24" x 3". Those were all old and some were heavily weathered. I made several boards the way I did the fish, and cut rocker slices for others that had more rocker. I make boards for the fun of riding my own creations, and I like to make boards I that others wouldn’t make. It’s been a fun ride and I’ve learned a lot.

Need anyone say more.  Shouuld be the typical reaction by any shaper who is ankle deep in foam dust and has been for the last 15 or 20 years.  Nuff said.

That’s a nice outline for anyone wanting to shape a Fish.

Honestly tho;  the volume of the Vortex created by water infiltration results in a negative volume plus two,

When “keel fish” or any fish board was first designed , no one really give a toss about how many litres they were…why ? …because it really don’t matter

That’s funny. I’m pretty sure the volume thing is only because of computer designs and machine shaping.

The ability to Scan an irregular (meaning other than square, round or rectangular) shape via CNC Computer has popularized Volumne calculation.  The average shaper doesn’t have a clue how to figure the volumne of something he just shaped by hand.  But he can call down to the cutting house and ask his “operator”;  “What was the volumne on that last 6’2 you cut for me?”

Well…every board has a volume, whether you believe volume “matters” or not. Shapers have been “doing” volume whether they think of it that way or not, and more precise designs will have more precise volume targets as the skill level increases and the closer the design is to an HPSB. A CT or just below CT level rider will be sensitive to diffences of 1L or less. “Let’s do another one just like this but 1/16 thinner, and maybe a bit more out of the nose” is in part a volume adjustment, whether you speak of it that way or not. This is just objective reality.

Volume will directly affect buoyancy – one more variable. 

The more data you have for each variable, the better chance you have of replicating/duplicating a “magic” board.

If someone orders a board shaped with X amount of litres , I’m wonderin’ how they check the volume when the board’s finished and ready to ride ?..you know , just to make sure it’s gonna work properly for them…(lol) .

i use to repair all kind of boards those last 25 years, from no name shapers to CT surfer boards. i measure many   and always be surprised how far real numbers are far from what is wright on blank, even standard length, width, thickness, so volume… most builder wright target numbers not real ones, volume number is an approximation, give an information but 0.1L accuracy is a joke.

double post