Single Fin Fish

I have a 5’6 X 19 3/4 X 2 7/16 Fish Surfboard ready to be glass. The shape is a full outline, with wide nose , and tail. The board is going on a trip to Peru, so It would be surf on beachbreaks, and some point ones as well. The fin setup is quad and single fin. I wanted to hear from people about the single fin set up on wide swallow tails. The placement of the tail, and any takes on this setup.

thanks

My experience with wide tailed single fins has been that they spin out easily if you don’t use a really long fin. A deep swallow might help let the tail sink down a bit more, and you’re still under 20 inches at the widepoint, so that helps, too.

Are you sure it’s not set up for a thruster and a quad, not a single? Got a pic?

I rode a 6’2" x21" x3" wide swallow fish in yesteryear and it had severe limitations in bigger faced waves. I recall taking only that board to Jalama and on larger days having to ride the board in more of a cheater five position (wide low stance) most of the day to hold it down from constantly spinning out.

The board had a molded wide base Brewer fin that if I recall right was 7-5/8H by 5-7/8"Base. These were the clear plastic thick foiled fins that came out at the same time Mike Hynson had done the pantographic Dol fin off Cindy at Sea World.

It was a tall order to expect this size fin to hold in well overhead facey waves at the J, but by widening my stance I could feel the length of the board and hold it down most the time.

I’ve been to Peru and many of the waves are large face waves…ala Punta Rocas. If you surf in Miraflores or La Isla, you probably won’t be challenged. There are a bunch of really quality beachbreaks like Puerto Viejo that demand fast down the line surfing, so the quad setup would be a priority.

I think using a big long single fin on a fish is counter intuitive to what the fish was orignally designed for.

In retrospect, I think if that board had been the same dims except about 2-1/2" thick, I could have powered thru sinking rail turn and surfed about 300% better…

Use Bill Thrailkills method to place the single fin, and you will not have to worry about spin-out. Just laying the fin over on its side in the approximate position will tell you if you need a bigger fin or not. Bill helped me place the fin on my single fin fish, and it is a magic board (length: 6’ 2", width 20.5"). I surf it mostly at Sunset Cliffs, and it has performed nicely in waves with ten foot faces. I did not like the board too much when I surfed it last summer in hollow beach break conditions. I don’t think it was the fin, though. The board just didn’t have enough rocker IMO. Fish aren’t supposed to have a lot of rocker anyway. I have been to Peru, and you will have a good time on a single fin fish. It would great for Punta Roca’s. I’m not so sure about some of the Northern spots like Cabo Blanco, though. You might want to bring more than one board.

Yeah, the methodology to visually see if the fin overlaps the rail on a hypothetical turn at the proposed placement up from the tail is a good layman’s way to check things out, but it doesn’t take into account rocker, rail thickness, bottom configuration (v no v, depth of of v…concave(s)) etc. etc…so although it is helpful it by no means is a real measure of how ultimately well the board will work.

Too simple with too many variables to guarantee a perfect result!

i’m STOKED to see / hear about someone else riding a SINGLE FIN FISH here !

i’ve been on them and on about them here* for years , without any success , it seemed …

so… **good **on you , mate , for trying it !

enjoy it , and …please…post some photos of it , eh ??

cheers !

ben

[ * see “chipfish61” 's posts , there will be mention there of single fin setup on my ‘prawn’ board , plus photos galore]

Thinking about the single fin fish I had…and that thick foiled Brewer wide base fin…if I were to do it over again, I would have tried a fin that was deeper…say 8 to 8-1/2" that had more tip area along with a fairly wide base. And I would have had a thin flatter foil than the thick very curved foil the Brewer had…these were molded acrylic fins done right at the same time Hynson did the Dol-Fin (a pantographic version borrowed from Cindy (yes, the dolphin) at Sea World.

If you use a larger fin, try more area in the tip and overall with a flatter foil on it for increased leverage and “grip”. You can use the layman’s placement method suggested for positioning up from the tail, but be cognizant of the depth of cut in your swallow and f you have vee or not.

Now here’s another weird oddity I have found with fins…and not just fish, but in general. Sometimes due to other design aspects of a board the age old wisdom of placing the fin back further for more ‘grip’ results in the whole tail abuptly popping out on turns…and moving the fin UP actually can improve things…which runs counter to what most of us were taught. The plausible explanation for why this works is that something with the last part of the tail rocker isn’t right for the further back placement, and by moving it up the increased maneuverability gained allows the board to turn better and enables a rail set by doing so. This could also be due to the plan shape aka outline…particularly on old style single fins, but less suspect with fish, that usually have straighter more parallel outlines in their tail section.

My call if you surf Punta Rocas with any size is the quad setup. I hope this board has some real edge on the rail tuck.

Vaya Con Dios Hermano

Hey, thanks for pointing out that the method of fin placement I’ve used so successfuly, for 49 years, was a ‘‘layman’s method.’’ I had no idea how inexperienced I was. I guess I’ve been lucky that since using the technique, I’ve never, (emphasis on never) had a board spin out. There is an axiom in design, engineering, and science, that the simplest answer is the best answer. I’m guilty of keeping it simple. Too simple? I doubt it. Other factors bear on the success of a fins placement, but the PRIMARY consideration is the relationship to the outline. The other stuff is fine tuneing. When selecting the point of fin placement, my method is to then set an FU box such that the fin is in the center of the box, allowing maximum adjustment fore and aft, to dial in the best performance. There are other nuances, depending on the rider’s preferences, and surf conditions the board is designed for, that come into play, but that is another discussion for another time. The above method, as you pointed out, is not perfect…but it’s close. It is intended to get you ‘‘in the ballpark’’, where little if any adjustment is needed to dial the board in. Is that explaination helpful?

Sorry about hitting that ‘nerve’ Bill…good reason for me not becoming a dentist! I didn’t mean to imply lack of YOUR experience by using the term ‘layman’…in retrospect, probably a poor choice of word. However, it is kind of a simple every man kinda way to get ‘in the ballpark’ as you say…and for the most park it works pretty darn well.

Some guys used to use the one base up theory for positioning, but you and I know that this could be misleading depending on what the actual fin is…I don’t think that application would work so great for a single keel fin?

I agree with you that the primary consideration is planshape, but I’m really curious if, in all your years, you never ran across the fin back pop out scenario I mentioned. I mostly attribute that to some anomally with outline, fin position and inability for rail set…what’s your opinion, if any?

P.S.

the fin pop out thing I’m talking about was during the single fin era. And call it my brain fart, but when I first read this thread I was thinking about those boards and a single fin glassed on…not a box as you mentioned…which I would do the same exact way as you outline…oh well, maybe it’s time to have the wife take me in to the vet and have me put down…:frowning:

in 1971-1972 our next door neighbor gave me his son’s junked up board which we promptly stripped cut the tail off and cut in a huge swallow and made a fish which I attached a home made version of this jeff ho feather fin below…

it worked unreal in 1-2 foot waves flexing and snapping back skateboard turns. the I stupidly took it outside to first break took off on a 3-4 footer hawaiian scale snapped the fin off the backside turn and snapped the board. put it back togethor as a “staged” rocker filling the gaps with bondo and slapped on two keels and rode it like that for the rest of its life.

so yeah singles on a fish work fine

feather

[quote=“$1”]

in 1971-1972 our next door neighbor gave me his son’s junked up board which we promptly stripped cut the tail off and cut in a huge swallow and made a fish which I attached a home made version of this jeff ho feather fin below…

it worked unreal in 1-2 foot waves flexing and snapping back skateboard turns. the I stupidly took it outside to first break took off on a 3-4 footer hawaiian scale snapped the fin off the backside turn and snapped the board. put it back togethor as a “staged” rocker filling the gaps with bondo and slapped on two keels and rode it like that for the rest of its life.

so yeah singles on a fish work fine

feather

[/quo

te] I wish I could read this Paul Gross Article!

Neat looking fin…yeah, my single fin fish worked good most of the time actually. I liked the board. It was pretty run of the mill off the rack kind of shape to be honest. I wouldn’t ride a fish in 10 ft faces like the other guy in this thread mentioned, but to each their own. I think fish excell in smaller waves, but as I said…personal preference.

NOhting is good nor bad, thinking merely makes it so…Shakespeare.

hiya kawika !!

…i have the article in question

if you pm me your address , i’ll send it to you if you like ?

cheers

ben

[i think i might have already posted it previously here on swaylocks [under ‘chipfish61’]…

[quote=“$1”]

I agree with you that the primary consideration is planshape, but I’m really curious if, in all your years, you never ran across the fin back pop out scenario I mentioned. I mostly attribute that to some anomally with outline, fin position and inability for rail set…what’s your opinion, if any?

Deadshaper,

Per the above question, yes, I have experienced what you described. The phenomenon is most frequently associated with the classic Pig shape, and the most extreme offender was the Velzy Bump model. The wide point of the board was typically one third of the board length up from the tail, in those designs. That wide point, close to the tail, when turned hard would pop out a nine inch D-fin set right on the tail. By moving the wide point more forward you would reduce, or eliminate, the spinout, because the pivot point of the outline moves away from the fin. I had an 8’ 10’’ Velzy Bump, in 1958, that I had to turn very gently, and somewhat flat, or the tail would leap out of the water, if I tried to lay it over on the rail.

Hi Bill -

It seems that the more I learn about designs and shapes the more I realize that many perfectly functional ideas from past times have been overlooked or just passed by.

I’ve used the “fin over the rail” trick but to be honest, merely guessed at how much fin area should actually be hanging over the edge. Is there a formula you use or some ballpark estimate like certain number of square inches? By simply eyeballing, I seemd to do OK but I wish I knew of a way to quantitate it better.

Regarding the original post… another question might be, “when is a ‘fish’ a fish?” By my reckoning a single fin swallow tail is a single fin swallow tail. A ‘fish’ is a wide tailed swallow with double keels and more recently quads.

Back in singlefin days, I would take the fin and lay it back on its tip to see where it lined up with the tail, I like BT’s method better.

As for fish, I maintain that a Dorado Dolphin is a fish with a broad nose and fairly wide tail and a Wahoo is also a fish but with a torpedo shaped body and a more narrow tail. However, they are similar, just like wide “fish” and wider plan shapes that are “fishie.” Similar purpose, just look a little different from one another.

John,

I use an ‘‘eyeball guestimate’’ of somewhere between 15% and 25% of the fins depth, extending over the outline. If the fin is to be a glass-on, I’ll tend to be more conservative, than if setting a fin box. For wider tails, more fin over the outline, than on gunnier shapes. In any event, I prefer to use a fin box for the ability to dial in the optimum position suitable to the shape, and rider.

I would suggest trying a Horan star fin, if you are trying to fin a wide short flat rockered board for jucier waves.
Swallow tail notwithstanding.
But, that’s just me. Your mileage may vary.

When is a fish a fish…oh boy, I’m not gonna follow this thread down that path. Probalby some lunch lady in earyl 1950’s Cheboygan termed the Friday menu “Fishsticks” and it rolled from there.

Seriously though, the tail config was a natural for calling them fish, but from there every deviation known to man could enter the arena after the tail designation. So we ended up with swallow…a dovetail but with curve, and a fish having deeper scallops more like a mermaid’s tail or…My earlier day fishtails were nearly all kneeboards. Cut was 11-1/2" with half dome twinnies.

BTW…where have all the kneeboards gone?

Saw an older gentleman on one Monday afternoon in PB. But can’t remember ever seeing someone using one before then.