Fin Placement on Big Old school fish

I searched the archive for hours & couldn’t find any info.The board is 6’6"

17&1/4" x22&3/4" x17&1/4" with a 12" tail tip to tip & a 7" deep crouch, 3&1/4"

thick.The rails are tucked under till the last 14" were they harden up out to

the tail.It is shaped from a clark 6’9"A.The bottom is flat with a slight v in the tail

from 16" out.My question is were would be the best placement for the fins ?

The fins are keel type 8&1/4" at the base & 5&1/4" tall foiled on both sides.Any Info. & all theories would be greatly appreciated since this is the first try at a

board of this style.I would like to keep the fins parallel to the stringer with no

cant or toe-in.Thanks in advance,long live Swaylocks.Brian.

I can’t believe you didn’t find more than you needed by searching the archives. Tons of info on fin placement there on a fish there. Try ‘fish fins placement’ and you get a ton of hits with the info you’re after. It’s hard to make head or tail of it though, it’s ALOT.

Recomandations in archive vary from 6" to 11" from tips of swallow, with around 8" being the norm. 1 1/2" - 1 3/4" off the rails. Also check http://www.surfline.com/mag/features/anatomy/

If I were you, i’d toe the fins in by a 1/4" to loosen it up a little. I used single side foiled fins on my 6’8" at 9" and set them pretty straight and the thing is a little stiff, stiff enough for me to install new boxes for the fins. But this is with a single sided foil, I think fin theory indicates that a double sided foil set straight will be a tad looser(and wicked fast!).

regards,

Håvard

I have a 6’4" Lis fish, the wooden keel fins are set paralell to the stringer, 6 3/8" from the tail, 1 5/8" off the rail. The swallow is not as deep as yours at 5". You may want to set the fins in line with the butt of the swallow, or 1 3/8" forward of the butt of the swallow like the one I have. I’m no fish expert but it seems that you don’t want to put the fins too forward like on a twin fin, where the fins are set somewhere around 9" up.

These plans were posted by Paul Jensen and are for a 5’5 Lis and hard to read…I have a high-res version at home. I could read what it says tonight.

The yellow board is my 5’8 Mandala and it is loose, doesn’t have any tracking problems w/ the parallel Gephart double-foil keels. In the shaping bay photo, the pencil marks for the keels appear to be toed, but that is due to the wide-angle lens distortion.

http://www.hollowsurfboards.com/Surfboard_Pictures/Board_7/Lis_Fish.jpg

10Toez,

I start a similar thread a couple of weeks ago. From the replies I got, it seems that 7.5" up is good figure.

The keel fins on my 5’10" fish are about 11.5" up which is definitely too far. The board does surf OK, but if my back foot is behind the fins the board is loose but has little down the line speed. When I move further up the board it is really fast but due (I think) to the flat rocker catches a rail easily when turning. I’m planning on moving the fins back to around 7.5" up.

10 toez,

My best fish to date has the approx. dimensions as yours. My fins are 9x5’s. I made sure the leading edge of my fins did not go past 15 inches. I cant remember where that puts the rear edge. I can go out and measure it if you want. The fins are 1.25 inches from the edge. My fins are single foiled and are toes in 1/8 " with about 3 degree cant. You might not want to toe in the double foils. Everything I learned about fish fin placement I got from this site and the archives. Keep looking. mike

Ten toes, my fish is pretty close in numbers to yours but is set up as a quad (Herbs Q4 style) with the big fins in back and smaller fins set in front. I put the main fins 8" up from the tail and toed 1/4" and set 1.25" off the rail. The board is fast and turns pretty good too. I think on big fish, a little toe helps keep them from being too stiff with all that straight rail line behind the wide point.

Hey Guy’s, as always thanks for all the info. keep it coming.Not to sound

ungrateful but, the only thing I’m not clear on is, how far in from the rail

edge should I place the fins.Thanks dubstar for the picture & the specks,

hopefully my board will look & surf as good as that one does.Just got my

pc back after almost 2 months, I can’t tell you how much I missed logging

on.Thanks again for the info. I’ll check the archives again with the post that

you guys gave me.Thanks again from a swaylocks addict !

You can put them anywhere from 1 1/4" to 1 3/4" in from the rail edge. I use a carpenter square to make sure they are the same from one side to the other and for measuring the toe.

Pic’s of Lis fish–The fins are parallel with stringer and double foiled 6 1/4inches up.Board has single concave and is capable of wide range of waves as long as they are clean.

Hi Brian, did you finish this fish?

What fin placement did you settle for?

How does it go?

Whats the biggest surf you have tried it in?

What positives and negatives did you find?

Would you refine it any where?

Could you safely go to 18" in the tail?

Sorry for all the questions but I’m about to building a similar fish out of the clark 6 9a blank.

Cheers Gaz

Hey Garzo,I finished the fish & road it for a month strait in all conditions from 2 foot

wind blow slop to cleen 5 to 6 foot faced pikes.You could go out to 18" in the tail

I don’t think it would change how the board works drasticly,I just don’t rembember

if the blank will accept that width.Fin placment I used:7 1/2" up from tips, 1 3/4" in

from the rail mesured at the back of the fin.The fins are glassed on parallel(NO TOE IN)8 1/4"'s in legenth at the base,5" 's in hight foiled on both sides.I added a slight

Vee in the tail so the fins(when glassed on the board flat) are canted out bacuse

of the Vee.The only changes that I would make to the board is,to move the fins

up about an 1 or so & get the 6 9 A with less rocker bent into the nose from 12" 's

out,maybe 3/4 of an inch but no more than an inch.All & all I’m so pleased with the boards performance,it’s real fast,catchs waves like a magnet,& has so much drive

off the bottom it’s unreel.It has become one of my favorit boards.Hope I covered

all of your questions sorry for spelling errors, no spell check.Good luck, Brian.

Thanks for the reply, nice to hear these big fish work well. I will go a wide in the tail a it lets me, sounds like great fun.

Cheers Gaz