Squashed Semi-Gun

I am hoping to shape a board (about 6’) that has plenty of volume for easy paddling into hollow waves(I’m also quite a weighty lad), but is narrow enough in the tail and short enough to be manoeuvrable. Coming from the uk most of our very hollow waves are slabby reefs, few wedgy beaches and the odd good beachbreak; so getting in early is important. So I have been experimenting with a few shapes and have come up with a kind of squashed semi-gun, which looks a lot like some retro single-fins I’ve seen about. Its likely that the board will have a lot of volume up from the wide point compared to your typical gun to make up for loss of length, but taper to a more regular rounded pin tail. I was wondering if anyone could tell me what kind of impact squashing this kind of design would have? Will the extra volume in the nose have any major downsides in steep hollow waves? I’m also concerned about what type fin setup to use, I see a lot of single fin setups on similar shaped boards but was wondering if a thruster or quad setup would work? Any sound advice or opinion would be gratefully received!

Sounds like you are talking about the Rusty Slayer or CI Deep Six type of board. There is an active discussion on surfermag’s design forum going on now that talks about these boards. I made a 6’2" (I’m 5’10" 200 lbs) x 20.25 x 14 5/8N x 14 9/16T x 2.5 thick board like this and I love it. Mine is set up as a quad and it works great for the hollow, short-period, cold-water waves we have here in NJ. Fits the steep faces much better than the traditional 6’6" stepup it was designed to replace and paddles just as well.



That looks pretty similar to what I have have measured out on some wood.going on your dimentions I may need to make mine a tad wider and thicker( I’m 6" and 230 pounds)
What about rocker? I’ve heard that the Ci deep six thing has less nose rocker, is this compensated for by more tail rocker? Are there any other traits of longer boards that can be used on shorter boards to help in hollower waves? Thanks for the feedbackk on the fin setup had always wanted to try a quad. .

First, I should disclose that I am very much a beginner shaper/designer (but a reasonably competent surfer) and this is only the 4th board that I’ve made.

That being said, I will outline my logic that went into the design:


  1. Basically, take your normal step-up board (mine was a 6’6"x19.5" round pin) and lop 3-4 inches off the nose. So your rocker is basically the same as the step-up board, without the front 3-4 inches. So if your step-up board has 5.5" of nose rocker, your “squished” stepup will have about 4.5". The fact that the board is significantly shorter seems to make up for the lower nose rocker in terms of dropping in on steep waves without pearling.

  2. For paddling, I wanted the overall volume of the board to be the same (or even more) than my normal stepup. This is why I increased the width by about 3/4 inches. In keeping with the “chop off the nose” philosophy, the wide point is now forward of center by about 2-3 inches. But remember that the wide point is still basically at the same apex of the rocker.

  3. I put in a single concave from about 12" from the nose through the fins. Max depth was about 1/8" at the apex of the rocker. Flat bottom in the last few inches behind the fins to the tail. Logic was to “straighten out the rocker” for speed when planing, while maintaining good outline curve and rocker while on rail and pocket maneuverability.

  4. Thickness was SUPPOSED to be the same as my normal stepup (2 5/8"), but the blank was pretty close tolerance and I ended up at about 2 1/2" (told you I was a rookie). I am in the process of making a new board that will be 2 5/8" because mine feels a bit thin, especially with the water temps dropping and the wetsuits thickening. Rails are fairly similar to step-up: lowish volume for easy penetration into the face dropping in late/angled.

So, based on your height weight, I’d probably do a 6’3 (max 6’4 to preserve the benefits of a shorter step-up). I’d do 20.5 width max. You don’t want to go too wide, because you still want to be able to get a narrowish (sub 15") tail without an abrupt transition from middle to tail. Thickness and foil should be the same as your normal stepup (2 3/4??).

But don’t take my word for it. Check out the Rusty website and the dims/description of his stock Slayer boards.

Good luck.

im 6’3 200lbs and made a 6’8x20ishx 2.5ish square tailed single concave into a V. really works well for those windswells in maryland and medium periods in NJ. on the blocks now is a 7’4 which is for those super heavy days.

Thanks for the feedback guys going to check out the rusty website now. Really looking forward to getting started on a few boards in the new year. Think i’m going to be pretty busy on the weekends. Will post up the results when i have started.


…like yesterday…