Been riding different boards and fins lately and it got me thinking. What is the difference between a single which would have a fat and wide base with a thin tip and a tri.

Coming to think of it MUF fins are a bit like that!

Are you saying you wish to get the same feel as a tri / thruster but with a single?
I don't think its possible, as the idea is the side fins move the fin area forward making it looser / better for wave riding than a single.

Good point forward so spread over a wider area...
The one advantage I can think of is grip or safety factor of increased and more reliable support.

Well still... No one rides singles in pozo, Maui, and such?

Hi
if you mean thick foil leading edge vs thin foil leading edge fat create more force gives lift and will have more power and will get you plane earlier but will have drag at high speeds
in the turn the amount of lift that a fin produces is in direct relation to the angle of attack So fat foil big range of AOA thin foil the fin breaks out more easily in a turn but has less drag at high speeds
if you push hard on the fin a thin foil could not handle big AoA and a bigger will increase drag reduce control manoeuvrability
wide base more power and drive thin base more manoeuvrability.
So you must find an optimum relation between drag and lift at the speed and aoa . Single fin higher speeds less drag tri fin manoeuvrability control drive .Hope it helps

I mean wider up top, looking closer black projects are like that, mufs, then Makani has some funky options.

I'd love to hear about fins with a cutout mid fin things like that!

black muf have mixed characteristics of those principles wider base of bigger fin for power speed drive in turns thinner tip for maneuverability Got mixed answers from people who tried black. Mufs are more straight with less rake favoring speed but i think less maneuverability wider arcs . MUF design claims //MUFfins delivers unmatched stability and speed range, unbelievably upwind performance, they are extremely spin-out resistant, great in jibing and agile on the waves.//

you can read the whole
1. What makes Maui Ultra Fins so exceptional?Maui Ultra Fins uses specifically developed foils which have been optimized for the windsurfing speed range and conditions.MUFins provide nearly twice as much lift at low speeds compared to conventional fins with the same fin area.MUFins also allow a nearly twice as high angle of attack (flow angle) than conventional fins.On top of this, the fins provide outstanding upwind performance and spin-out resistance and even the drag is much lower compared to conventional fins which makes MUFins so fast.All these characteristics allow a very stable ride and jibing in all wind and wave conditions. 2. Why do our fins have no flex?When sailing, the wind can be very gusty (sudden change in wind speed and direction), which leads to sudden changes in sail forces that are very uncomfortable.To compensate the varying forces sail tip flex was invented that lead to very easy sail handling.However, there are no gusts in the water which have to be compensated. Due to the fact that the airfoils of conventional fins have limited spin-out margins, flex was introduced to reduce the spin-out problem. But as a result performance is lost.Because MUFins are so spin-out resistant, flex is not needed and full performance is available in all conditions.Fin evaluations have shown that no flex is preferred. 3. Why do our wave fins not have the typical wave fin outline?To start with: The typical wave fin outline is regarded as highly inefficient under hydro-dynamical aspects due to the extremely high rake (swept back) at the tip.To provide flex in wave fins, airfoils ended up being very thin at the tip which results in early spin-out.Our impression is that the wave fin outline was heavily influenced by simply copying from sea animals, when fins first were used on surfboards. Since then the outline has never changed and few people have questioned this approach.Many tests of MUFins in wave conditions have shown that they work perfectly in small waves as well as in really big surf with their elliptic and relative straight shape. 4. Why do our fins have an elliptic outline?The so called induced drag of a fin is produced by pressure equalization at the tip of the fin. This drag is minimal, when the fin outline is elliptic. This has been well known for over 80 years.That's why MUFins have an elliptic outline - to reduce the induced drag. 5. What is G-10 material?G-10 is a glass epoxy laminate which has been used as electro-static dissipative material. It is very stiff and it offers excellent machinability and tight tolerances.All Maui Ultra Fins are made of high-quality G-10.

MUF fins are sick! Heard great things about black project too. They both have wide bases and thin tips.

Can't find an image of a fin with a cutout section in the center. I think this could increase grip while minimizing drag.

Singles are much harder to recover from spinouts than multi fins.

I have little experience with fins but i used both muf and bp freewave fins.
I didn't like them because they felt really stiff, maybe i should have chosen one size smaller for these kind of fins but probably stiff characteristics would still be there.
Later used similar shape but thinner g-10 fins and had better results. Now i prefer softer material fins like k4 or mfc makes.
These lead me to think flexible (usually thinner) fins are good for lightweight riders.

Do you sail well powered up or at least strong waves? Or do you have some light to medium conditions where planing is off and on?

I have been reading comments on wave fins until I switched to K4. Period.

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Manuel7 said..
Do you sail well powered up or at least strong waves? Or do you have some light to medium conditions where planing is off and on?

Used muf x-wave as trifins center fin on severne dyno, b&j conditions, light and strong wind. Compared it to original fin, which is olso upright but a little thinner (v1 fin), original felt better but not with a big margin, plus side was muf solved my spinout problem at that time so i prefered to use it. Side note on muf: Group of people i met who used and recommended me muf fins were all big guys from eastern europe.
Used bp kraken as single fin on dyno, b&j conditions, light and strong winds. Compared with Drake freewave, which is more swept back, narrower and thinner, much better feeling for me, especially in strong winds.
Olso compared to tribal kruze, which is an upright freeride fin, still thinner and much narrower, clear winner for freeride.

Compared mfc trifin center in g-10 and softer rtm constructions on goya c3, wave conditions. Light wind planing performance was better at g-10 version but rtm was better on waves and in strong winds, they both felt good though.

Recently compared original patrik f-wave g-10 fins (relatively thick, narrow and upright fins) with k4 scorcher and ezzys, strong and light wind b&j with wind swell. Night and day difference both in straight line comfort and especially in carving performance, maybe just slightly harder to pump into plane, but loving the combo now.
Compared k4 3sw and dyno v2 center fin as single fins on patrik f-wave, medium wind b&j conditions. Again, k4 felt better, but trifin is much better.

From an old sb thread:


Wondering if possible to get more grip while keeping a single for less drag...

I've ridden a slotted fin, it was slow.

haven't got time to comment , as this subject so broad / diverse and too many caveats ... but .......@Manual7 - love how enthusiastic about windsurfing you are ... good on ya ...

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Grantmac said..
I've ridden a slotted fin, it was slow.

Not sure what they are meant to do but was thinking that the slot would be farther back and longer.

Slotted fins were used to prevent spin out, haven't used one since the 90s

pretty sure those are my slot fins :-). or were once as i sold them. the torquay worked well.

the thing i find with fins is it's real obvious if they are good or not within the first hundred meters. if you are still wondering after that if the fin is ok then it's not.

I'm not much of a wave sailor but i prefer softer fins for freewave / waves. stiff for slalom/race/freeride.

i do have a tectonics g10 wave fin tho which is stiff and it's excellent.

having bought and sold a lot of fins because i have a gambling problem with fins i'm now at the point where i'll only buy

MFC, Choco, SSD custom, tectonic (wave).

recently started fixating on a flikka fin or 2 to try. really like their thoughts on fins so that's the next gamble