Semi-gun science

General Discussion
1

I need some insight on dimensions, bottom contours ect. I just picked up a 7’3" R and I’m looking at making a 7’2" semi-gun

for mid-Atlantic beach breaks in heavy winter conditions, full rubber the whole nine yards. It will also serve a duel purpose for hurricane season and travel. The local conditions I deal with when its on is a slab that jacks on the sand bar at the last second and goes square quite properly. It tends to burn down the line on a long period swell( for my local meaning 13-14 second). I need quick paddle acceleration and the rail needs to set immediately. The lefts are what kills me as far as getting in on my backhand. I’m, hoping this board will remedy some of this b/c my standard 6’4"- 6’8" thruster isn’t doing the deed when I have a 5 mil on in 37degree water. I’m also 6’ 175lbs and pretty fair paddler.

What I had conceived was a 7’2"x 19 3/4" x 2 5/8" or 2 3/4". 12" wide nose, not sure about the tail? suggestions. The rocker is going to be key so some nose and tail measurements would be nice. The natural rocker of the blank doesn’t seem too bad, but I’m sure someone has some good suggestions. The wide point location I’m unsure of. Center or 1" above center was my thought. What bottom contours do you all think would work best? I was thinking flat to vee off the tail or flat to spiral vee? Not to worried about chop b/c it’s usually hard offshore when a Nor’ Easter blows through. Lastly any good suggestions on rail shape. I figured the deck would be domed and wasn’t sure what would work best. I want this board the sit in the face and set a line so I would assume I don’t want my rails too corky. Also I’m going to glass it heavy, double 6 oz. deck single 6 oz. bottom Thats all I can think of right now. Thanks in advance for everyones knowledge, it’s greatly appreciated.

2

gunny board and hollow waves - generous on the tail kick - 2.5" to 2.75" rear rocker

hard down rails

Reverse vee, that is vee under the front foot carried all the way back to the fins, then flat through the back. Works great on a gun. Or, just do a tri-plane. Depends on how stable you want it - the reverse vee for stability, the triplane if you want to bash a rail. A 7’2" is short enough you can still throw the board around a little.

rounded pin tail, around 12.75-13.25 inches wide, keep the wide point a little front of center - maybe 2-3 inches.

12 inch nose is ok, maybe even 1/2" smaller

3

EZE- I started a post called “difficult takeoff” which is about the same type wave but in the head high range , some info there might be helpful to you. That 7’3" R , if it’s the natural rocker has 2 1/4 " TR. I think that tail rocker works best on a wave with a drawn out drop, rather than a steep takeoff. I have a semi I feel real comfortable on in about 8’ waves . It’s 7’1"x19x 2 1/2, 11"N 12 3/4" T, 3" squash tail, 2 9/16" TR, 6"NR (I weigh 150 lbs.) bottom is a little v in the first 18’ of nose to a very shallow single concave to front foot, v and shallow double concave between the feet and flat out the back. The little squash has allowed me to make drops I couldn’t make on the same board with a round pin. I “borrowed” most of this design from a Rawson made for Tom Carrol. I’d say it’s the best semi I’ve owned .Good Luck. PM me about that blank rocker and foil if you wish.

4

The lefts are what kills me as far as getting in on my backhand.

railgrab is the key…years ago, dropping in backside was one of my weaknesses but with a railgrab now its one of my strengths, to the point i actually prefer steep backside drops over frontside. watch any regular foot pro drop in on chopoo, every one grabs the rail. yeah proper equipment helps but im taking the 5th on that these days…

5

The trusty pig-dog isn’t the problem it is having to build up that quick head of steam for the take off and getting forward projection in an instant.

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Ole’ Blakstah basically said what I was gonna say…

I’ll add that you can go flat deck, thick rails, and offset that by softening the edge on the rails for hold (water wrapping around rails is holding power). Hard tail rails, last 18" or so.

If you like crowned decks and soft rails, go for it.

Those quick pitching waves are up to the surfer to conquer, not the design of the board.

The boards gets you into position, then the surfer has to hold the tail edge and not fall off, while getting an angle to make the upcoming sections.

7

…is having to build up that quick head of steam for the take off and getting forward projection in an instant.

a std mainstream sg’s work good…more toein lifts the tail up quicker…thicken your tail a bit…use buoyant fins…kick your feet as hard as you can…paddle as hard as possible without too much hand ventilation - elite swimmers have a simple trick for this…yup i love science…grab your rail backhand (my favorite common surfing experience)

…take up hard paddling or swimming in preparation…if you cant make critical late drops know that youre not alone…its a big club

8

To reiterate what these guys already said…in a nutshell…(funny that 3/5 of us respondents surf OB, SF)…

Round pin tail so you don’t get jacked with the wave

Hard rails from leading edge of side fins back, softer otherwise for hold

Blocky rails not pinched so you can commit your weight way out over the rail but it won’t dive in

Pig dog pig dog pig dog

have fun

9

" Those quick pitching waves are up to the surfer to conquer, not the design of the board.

The boards gets you into position, then the surfer has to hold the tail edge and not fall off, while getting an angle to make the upcoming sections. "

I could not agree more. for me its an attempt to understand how my shortcomings as a surfer are reflected in what I can or can’t make a certain board do…

i.e. TomCurrens never gonna say he can’t make such and such a steep drop on a 14 1/2" tail…

Yet that may be totally true for you or me.

Sometimes my most humbling, frightening, or embarrasing moments have also been my most instructional

i.e. “I’ll never try to ride such a (short/long/wide/narrow/thick/thin) board in such a (big/small/steep/mushy) wave again (and I hope no one I know was watching :)”

So some of us can ride any board in anything, some of us want the tail pulled in a 1/2" or 2" longer or whatever, and some of us just say d’uh? (or duh’oh)

So I answer yer question with a question: What are you having a hard time with? paddle out, not catchin em, catchin em too late/deep, gettin pitched, pearling, too wiggly or stiff at the bottom, got yer line but don’t like how the edge feels, too slow/loose or fast/stiff? etc. etc. try to figure out what it is about yer current board thats contributing to the issue.

A shaper I’ve worked with forever told me once “what feels right to one guy may feel totally wrong to the next one” his point being that it comes down to what feels best to you. So while our collective knowledge base has achieved guiding principles so we all can agree (mostly) on how an 18" differs from a 21", its still totally subjective when it comes down to us determining what too wide or narrow, flat or rockered is for ourselves.

My approach to that has been to keep a detailed record of the dimensions of every board I’ve ever owned, relentlessly borrowin/riding/measuring anything I can get my hands on, and then telling my shaper “such and such feels more or less this or that” he never hesitates at calling B.S. on it when I’m way off anyway :slight_smile: - usually it leads to my next board ‘solving’ some of MY deficiencies as I realize “I sure as hell can’t take off on a wave like that with a 14 1/2” tail"

I think that through this process I am and have been slowly but surely 'getting somewhere" over the last 25 years.

I think if you look at every board you’ve ever ridden in this way that trends emerge.

This compensates nicely for my shortcomings in similar conditions to what you describe:

7’6" x 18 3/8" x 3"

10 7/8" nose 11 3/4" tail wide point 2" fwd

5 1/2" nose rocker 3" tail rocker

fins 12" & 3 1/2" (big-4 5/8")

single->double 3/16"

highly foiled & low railed

I am about yer size 6’1" 195 lbs

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Here is a 7’2 x 20 x 2&3/4 semi gun and 7’6 x20 &1/2 x2&7/8

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Quote:
The trusty pig-dog isn't the problem it is having to build up that quick head of steam for the take off and getting forward projection in an instant.

It sound like you don’t have enuf umpf at the moment of thuth - if this was me I’d go less rocker and/or more thickness/volume.

yaaaaaaar!

12

7’3" 11.5-20-14.5 x 2 3/4

From a 7’4"R

This is what I’m riding in big winter East coast swells.


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ONE surfer trick for getting into big, pitching surf is to wait till the last second to paddle, so you don’t wear yourself out with more than 5 strokes. Late flip, shove board under you a bit to get pop, then really sprint and angle your nose a bit to get more face to work with. You gotta commit, drive your head over the hump, and get the board angling down the face.

Pig dog or not, don’t really matter, it’s kinda classic to make it look easy, and stand up.

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Double barrel concaves.

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Thanks to everyone who contributed it gets me started on the right foot. I’ve been reading the posts and pining over pictures of some outstanding boards on this sight since 2001 and never posted but a few times but have gained some serious knowledge about the thing I’m most passionate about. Surfing and surfboard design. Once I finish up my project I’ll post some picks and give you guys a look see at what you’ve helped create.