Retro fish tail

Hey guys 

So I’m shaping a retro fish from Steve lis original specs but I beefed it up a little. So it’s 6’0 / 22" / 3" but the issue I have is the deep swallow tail my tail is 2.5"thick, now my question is should I thin the whole tail down to 2" or just shape the inside of the tail down from 2.5 and if so how do I shape so inside wings thanks 

Hi Nberg. 2.5 inches thick at the tip of the tail or 12 inches up from the tip of the tail?  Regardless, that’s pretty thick and your board might need more foiling.  It would be helpful to see a picture.  Get your board 90 percent shaped and sanded before cutting the butt crack so you don’t snap a tip off.  Typically, the depth of the crack is 1/2 the distance of the distance between the tips.  Ex. 11 inches between tips and 5.5 inches deep. You can use a fin to trace the inside curve of the crack or any pleasing curve.  My personal boards are between 10 and 12 inches between the tips and the crack is 6.5 inches deep.   Mike

even two inches is very thick for a tail. Most of the fish I own and have shaped have a tail around 1" thick or  1.5" my favorite fish to surf is a twin with adeep swallow and is only an 1" thick in back 9 " of the board it is wild to ride in clean chest high I feel the tail flex with every turn 

It’s 2.5 at the crack and should I take    The whole board down because I want to keep the middle 3" 

This is what foiling is all about.  I’m not a big fan of computer design programs, but one thing they force you to do is consider the cross sections, in both directions.  I suggest you get your hands on a fish, or any surfboard really, and with a pair of calipers, measure the thickness in various places, to get the concept of how a board is foiled in order to keep the thickness where you want it, and shave it down where you don’t.   If you look at a typical stringer, you would see that the board tapers middle to front, and middle to back.  Most boards also taper from middle to rail (called dome deck), but some keep the deck pretty flat out to the rails.  There are a lot of options, and you, as the shaper / designer, have to control the process in order to control the finished shape. 

There is nothing wrong with your foam blank, but I personally prefer to shape the foil into the board, and shape the rails, before I cut the fish tail out.


Hi Nbergmann -

I think it’s looking good so far.  This is a good time to double check your template for squareness throughout and to make sure it’s as symmetrical as possible.

I recently, in another thread about thickness, posted a link to the old Parmenter ‘Surfboard Anatomy’ article which has specific dimensions for various shapes including fishes.  I will post a link to that thread here.

If you check you will see that both ‘fish’ and ‘post-modern fish’ are included with the p-m fish having the thinner of the tails.  If you go with something in between, 1 3/4" might be about right at the 12" mark. 

Here are pics of fish tails showing the stringer between the tips.  I go for basically this sort of stringer treatment on all my fish tails. I use a hacksaw blade and cut in at an angle to the center of the stringer from either side.  A round file is handy to have to smooth it out. Be careful of the foam on either side.  

It’s not the easiest part of a shaping job and as Rooster points out, watch out for those tips while shaping the crack.


Hi Nberg. I’d say your board needs some more foiling.  Foiling, in my opinion, is what separates real shapers from the garage hacks and hobby dablers.  My advice is to foil out the nose and tail, but don’t over do it.  If it’s a bit too thick it will still skate and run down the line.  

Nice buttcrack John!  Mike

Hi Mike - The bare foam is one I did.  The other is a photo I snagged someplace.  You may remember answering some of my amateurish questions regarding fish tail design?  I figure I received excellent advice from my consultant regarding general width/depth formula for the outline, as well as fin placements.  With minor variations, it’s all worked out well on subsequent boards.  THANKS!

Hi John. I don’t remember, but I do know you shape professional quality boards.  I don’t. Yet. 98 % of what I know about board design and building I learned here.  Mike

In the tail area, shape deck down, shape bottom up.

Both will reduce thickness.

yes, this is where foiling comes into play.

Most beginner’s fail to see this until many have been shaped.

Some never do.

Good luck.