I ride alot of finless boards, and they do seem pretty quick, although they’re difficult to generate speed on through pumping, but it is fair to say the entire rail acts as a fin, Quads and twin fins are the fastest on a surfboard, in my opinion. It has nothing to do with the size of the fin in quads and twins, but rather the placement being along the rail, where the water has already been broken and there is less initial drag hittting the fin. A single fin or even a thruster has a center fin, or anchor, that is cutting through clean unbroken water and has to fight the forces of drag alone…
So what I’m saying is that, 4 fins have a lot more surface area, but to accurately compare them to a single fin, they would have to be lined up perpendicular to the stringer and far enough away from the edge of the board to have no benefit from the rail.
A Strain test like the Lindsay Lorde used would best answer this question because the craft would be floating and just the fins would be submerged.
You don’t really believe that, do you? Think of the other P word, as it relates to the fin placement.
EDIT: Parallel. (to the stringer)
seriously, how much faster do you need your boards to be?
board control and placement determine whether you make the fastest of waves.
one of the most telling remarks made during the just completed Tahiti contest which according to Slater and Occy had the fastest, hollowest, best waves ever seen in a contest?
That a lot of the surfers chose thrusters over quads because they didn’t want to outrun the tube.
And note the tail pads they used, most covering the rear quarter of the board almost all the way to the rail apex. Factor that when deep in the pocket and the foam ball has covered the board, with a leash dragging along to boot.
The average shoulder to overhead waves that most of us surf? Making the board you’re riding a micro % faster isn’t going to change the made wave count. Upping your conditioning and technique will make far more difference.
Todays average well designed boards are hella fast. Todays average surfer, maybe not so much…
No Fin = No Drag.
No Board = No Fun
No Swaylocks = No Strange Discussions About Fins
so: Nf = ND
or nB = nf
therefore NSDAF / NF = Nb * ND
Ya all are crazy…my quad is faster than your best board in waves up to 1.5 head high. $100 says so
OK Bill, I’ll bite
Taking a clue from Everysurfer’s “warm” comment:
Fins have dual role. They provide forward direction and we foil them to help that and reduce the drag they induce. Fins also help provide lift or hold the tail in the water when on rail. We adjust rake and tip foil to influence this aspect. If we also think about “eliminating” or “adding” drag in different places, in addition to foil, we can reduce the fin size by increasing its effectiveness.
Different concepts I’m testing
just trying to find out for myself
don’t know if its related, but I like to find out for myself
instead of theorizing
Take away drag and boards don’t work…at all.
Yep. It’s what made the Hot Curls work. That V in the tail, settled the tail deeper in the water, thereby increasing the drag component and providing directional stability.
…most comments have valid points but in my opinion, we have 2 “worlds”; I mean, is not the same cruising down the line in a big board (with lots of volume) than riding a 5 8 / 6 HPSB…
The difference in those riding styles is what makes the difference; so the physics principles do not have been changed but the surfboards designs to fit them according to the biotype, wave/riding style.
Really not the same to try cruising (not searching for the wave pocket, etc) with a tiny thruster potato chip in a gutless wave in comparison with a single finnned big bulky board.
Yes, it’s counter intuitive. I don’t buy it unless someone can provide some sort of objective measurement data. Until then I’ll just say smoother is faster acknowledging I don’t have any objective data to support that either. I have touched dolphins and many fish and they are all pretty damn smooth with the exception of the sharks and their miniscule dentricles. mike
You just couldn’t feel the dermal ridges on the Dolphin. There’s lot’s more to the story of how they go so fast. Remember this takes place on a very small (molecular) scale. Remember too, that you are tapping into the kinetic energy of the wave, to propel you.
The constant need for “objective measurement data” doesn’t seem to be producing any groundbreaking results , as far as I can see…good fodder for discussion , but lacks the results that a more practical approach continues to deliver. Real life testing is still the dominant benchmark…marketing is just a speedbump that slows things down.
If you want “objective measurement data” you first have to define what is “faster”.
Have a look to cars:
The ThrustSSC (763 mph) is optimized for high speed on a straigtht line: low drag, minimized downforce.
A formula one car is otimized for high speed in curves: lots of drag, lots of downforce, lots of grip.
So which car is faster?
You have to decide what you whant to do with your car.
You cannot say that low drag is lump-sum faster.
My quad v. yours… -
True. It hasn’t produced any groundbreaking results that I’m aware of. But, real life testing doesn’t seem to producing results either. Just more anecdotes and plenty of bullshit marketing. I’m looking at only one variable, speed. The shortest time period between to points. Distance/time. Mike
Hi Bill. Yes, I’m sure there is way more to the story. Tapping into that kinetic energy of the wave is what the addiction is all about for me. Just wondering how to measure the increased speed. To see if it is real. I do think the questions can be answered with good scientific method. A well designed experiment. Mike
Sales and subjective perception – add celebrity and the recipe is complete.
Everybody knows Kelly Slater would surf faster/better if he rode a pointed red board with flame graphics. Add a Billabong and Red Bull sticker or two with the right logo. Then say altered boundary layer with a hydrophobic skin and sub-atomic ridges. Holy Sh!t!
(Damned little objective quantification of multiple variables to date. And the few who might be ain’t talking…)
I suppose the trial and error surfboard evolution over the last century could be called data collection – maybe more like punctuated equilibrium.
…
I had to ask. Does this assume light and faster than light velocities or bending the fabric of space are not possible?
in surfing, we want acceleration not top-end speed IMO.
as it is now in “normal” (under DOH) size waves, our top speed is sufficient.
it’s the time that it takes to get to top speed that drastically alters the ride.