Here’s one that definitely isn’t on Swindler’s list. . . .
The squidtail.
It’s actually on the board James is making, in fact he set the fins today. . . .I sneaked in and nabbed some pictures, special effects to protect the innocent. … . if it goes well we are going to have to have a wee talk about who what where and how the board will be ridden, without any standover tactics or anything, just friendly like.
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gotta say-it’s the fins more than the boards that intrigue me…
Wow! just what inspired his open-mind?
Please share the results
Oooohhh…faaabulous.
Whatever I said was gonna sound like Warhol anyway, so I might as well go all out.
You guys just plain rock. I love extra-boxular thinking. 
How’s it go?
(Not that that’s even the most important thing - the crucial part is the idea & how it gets people thinking & talking…)
Thanks!
Not sure how it goes yet Benny. . . well we can deduce certain things, bottom line is that if it holds in it is going to be great, it’s got a fair tweak of lift in it, and the board is twangy and thin ( An inch and seven eighths thick ) so it will be interesting.
James built the entire board, I just sat in the moaning chair making suggestions . . (Like if you cant be bothered foiling a carbon fibre bulb tipped flex fin, then how about just hacking a tunnel in two and bunging the pieces over by the rail ?. . after all we have a whole box of them ! )
As for extra boxular. . . we feared that the thing might be mistaken for a quad !
or even worse, a thruster !
Hi Roy , in the 2nd pic, with the 1/2 round fin, have you foiled both sides of the leading and trailing edge ?, it looks like the L.E is but the T.E is not…?
Or should the question go to James?
Regards, spuuut.
( Im still diggin’ the videos Roy)
Get some of James on his creation please !!
Here’s one that definitely isn’t on Swindler’s list. . . .
The squidtail.
It’s actually on the board James is making, in fact he set the fins today. . . .I sneaked in and nabbed some pictures, special effects to protect the innocent. … . if it goes well we are going to have to have a wee talk about who what where and how the board will be ridden, without any standover tactics or anything, just friendly like.
.
Wow! just what inspired his open-mind?
Please share the results
I think its genetic. . . . or environmental influence. . . or both !
Will let you know how it goes. . or James will, not sure if I’m going to get a turn on it yet, still waiting for swell, El Nino is at it again.
…
And a fine man is he !
Hi Spuuut, the fins are all flat on the inside, foiled on the outside,set up with a degree or two of lift against the bottom and a hair of toe in (just to make sure that there is no toe out)
It certainly looks like fun, hopefully James will move forwards with it rather than sideways
…>>
Hi Roy, love the joke at the end!
WOW, flat on the IN side, never wudda thought of that.
I would think that if they were flat on the OUT side and foiled on the inside like a planes wing,(albeit a curved wing), it would have kept with the established theory of lift.
Why is it so Roy? Why reverse the foil?
And with the “hair of toe-in” and opposing outside foil , arent the forces of the foil pulling away from the centre, rather than concentrating towards a focussed ‘eye’ of lift where the toe-in is aimed?
Spuuut.
Pardon me Roy, (and Brett, tsk tsk, you’re having a pick at the man)
if you use annular wings as models (and I’ve built paper ones [gliders, mind] and they’re foiled the way you describe, and the image I have of a certain airplane with a certain pilot shares this) the foils are on the outside of the annular wing the way you describe.
ON annular wings, the active lift is happening at the top of circle unless the plane has rudder applied (and aileron?), when the sideward upper quadrants of the circle also come into play. (It is interesting that you don’t see more gliders with annular wings, too)
On your tunnel, the foiling you describe would pull the tail down into the water deeper. If you felt lift back there, and I’m just going on apparent physical properties, I would say it’s likely the huge, heavy, rockered forward part of the board defeating the pull of the demi-annular orbulator, and teetering the tail skyward.
I have to say I’ve never noticed any apparent lifting dynamic about your tails in the vids. The roostertail always looked to me like it was release off a sunk pintail with a big round rail. And you would think that at certain high-speed moments, you’d have to get back there in a hurry to weight the lift back down…
BTW, I am not having a quick pick and run, or a snipe, or a bash, I’m just discussing some physical properties. Your turn.
Hi Janklow,
Regarding annular wings on aircraft, the lift isn’t just at the ‘top’ of the wing. . . the entire wing lifts by redirecting a cylinder of air. . . . Bernoulli’s priniple isn’t the best way to understand what’s going on with annular wings. Successful annular wing aircraft can be built with foil on the inside of the wing or not.
On my tunnel, the foiling I describe does not pull the tail down into the water. What happens is this: The asymmetrical foil means that the flow coming out of the tunnel is directed slightly towards the bottom if the tunnel is set up parallel to the bottom. What we do is to set up the tunnel at sufficient angle of lift so that it directs the water flow parallel to the bottom or slightly away from the bottom. . . it’s like the difference between toe in and effective toe in. The best way to think of the tunnel is a water flow direction unit.
Your idea that the weight of the nose of my boards accounts for any apparent feeling of lift by a seesaw effect (nose pulls down rocking tail up) . . sorry that’s not at all what happens. . . in fact if the nose is weighted the tunnel pulls the tail DOWN. . . and when the tail is weighted the tunnel drives the entire board UP.
The videos you have seen are all with tunnels set up to direct the water flow parallel to the bottom. . . so they don’t lift against the bottom they lift with the bottom … . . . they drive the board in the same direction as the bottom surface does . . . if the board points up it drives the board up, but it doesn’t push vertically against the bottom.
For lift against the bottom, we just crank the lift angle upwards in relation to the bottom, this has a dramatic effect from the riders point of view .
The board shown is the first board I have built since 2001 with the tunnel lifting against the bottom, the last one was the board shown below.
By the way we have done tunnels foiled on both sides and flat on the inside, and the effect is the same, apart from the need to set the flat foiled fin up at a slightly greater angle
Hi Spuut,
Think of the tunnel as a hose. . it directs a cylinder of water. . . and if the hose is pointed away from the bottom it lifts the board.
Bernoulli’s theory doesn’t help much with annular wings, the Coanda theory is more useful.
It might be useful for you to visualise an aicraft with a wing foiled more on top than on the bottom (as is the norm). Such an aircraft can fly perfectly well upside down. . . the Coanda effect explains this . I was discussing this with a pilot of aerobatic aircraft recently, and he told me that one of the aircraft types he uses was made with a symmetrically foiled wing and an asymmetrically foiled wing (two different versions) . . . both aircraft flew upside down perfectly, but there was a difference in the trim angle of the aircraft because of a difference in the direction of airflow coming off the two different wing sections.
I’m not thinking you can bring Coanda to bear here Roy. The Coanda effect involves an actively accelerated stream through the cylindrical body, whereas yours is passive, ambient flow speed. Your tunnel is a just a cylindrical body passing through a water mass, with no active acceleration. Unless you foiled the inside and you could claim a venturi. But even that would slow your board down.
SOme interesting things to look at here:
http://home.cinci.rr.com/estople/weirdair/weirdair.htm
All Coanda-utilizing VTOL aircraft use engine thrust directed through cylinders.
Interesting that you and Kevin Casey both found a surf-related for the firehose effect! LOL
I’m not thinking you can bring Coanda to bear here Roy. The Coanda effect involves an actively accelerated stream through the cylindrical body, whereas yours is passive, ambient flow speed.
Quote:. . . .. No, the coanda effect applies to gliders as well as powered aircraft. The Coanda effect simply means that the tunnel will redirect water flow in the direction in which it is aimed, nothing could be simpler. . . . <div class="bb-quote">Quote:<blockquote class="bb-quote-body">All Coanda-utilizing VTOL aircraft use engine thrust directed through cylinders.
. . . A VTOL aircraft is by definition a powered aircraft. . . . so your argument is irrelevant . . … . . Coanda effect is just water or airflow redirection. . . redirect the water flow and you get lift, it’s that simple . . …
Interesting that you and Kevin Casey both found a surf-related for the firehose effect! LOL 
Funny ha ha fact is that tunnel redirect water flow. . . a very simple thing to understand. . . excuse me for using an analogy when you are smart enough to understand the effect of water flow redirection directly.
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The Coanda effect is a good explanation for all wing based lift.
Consider the following points:
(1) Aircraft with asymetrically foiled wings can fly upside down. . . thus producing lift. … . the Coanda effect is the only way to explain this fact
(2) Annular wing flying toys exist which have no wing foiling at all. . . the wings are just flat surfaces. . … and they fly very efficiently. . . . . the Coanda effect is the only way to explain this
(3) We have had exactly the same results from tunnel fins foiled both sides as we have from tunnel fins which are flat on the inside and foiled on the outside.
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I would think that if they were flat on the OUT side and foiled on the inside like a planes wing,(albeit a curved wing), it would have kept with the established theory of lift.
Spuuut.
You mean one of the established theories of lift (The Bernoulli theory)
The Bernoulli theory fails to explain how lift is obtained from flat unfoiled wings, or from wings with foil on the underside.
The Coanda theory explains these things perfectly.
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Looks really cool, but I think the closed loop would be a kelp catcher. You’ll be cruising along nicely, and then all of a sudden everything will just come to a stop. I have heard that this happens with winged fins. I don’t know if you have kelp in your area, or if you care. Here is a modification that might let the kelp flow through, but still provides some lift. Sorry for the crude drawing. I’m not much of an artist.
Yikes ! you made it into a 4 fin !
We don’t have much of a seaweed problem at all, probably a tunnel with raked single in front would shed weed ok.
Here are some more pics;
