C4 Monofin!

[laminar]

$75,000 anyone...anyone...

[trux]

Originally Posted by laminar

$75,000 anyone...anyone...

Yes, you can count on me - I accept any amount of cash anytime. Just send it my way

Originally Posted by Fondueset

So it doesn't turn into a test of technology.

That's actually the wrong way. What I expect from competitions is the same I expect from F1 races - technology improvements. Competitions are the best place to test inventions and see what technological modifications lead to better results. So artificially limiting the dimensions, shape or other aspects of the fin makes no sense to me. If a better fin can bring me farther or is faster, why would we ban it from competitions? That makes no sense to me.

Originally Posted by jome

I very very briefly tried one of those C4 fins and...(drumroll)...The impression was "meh"....

Well, I just came back from the training where I asked Cedric Genin who also briefly tested the C4 monofin in Italy, and his comments were even much more negative. He did not like it at all. He did not even like the foot pockets - they may look cool, but do not seem to be well suited for the use on monofins. His comments were very negative and almost not publishable, but I realize that they were very subjective and based on only a very brief experience, without the chance to experiment with it and trying to find a more optimal kicking style.

Unlike what Spaghetti wrote, Cedric told me that C4 introduced the monofin as a finished product, not a prototype, and also mentioned price of some €600 (which might have been also a reason of his very critical view)

Originally Posted by Mullins

To clarify why I think current monofin design is inherently dodgy and longer monofins even more so: there should be one optimal angle of attack for a blade surface to propel a diver forward.

Me too, I believe that the current monofins are very far in efficiency from what they could be. However, the hydrodynamics is little bit more complicated, so just having a fin with ideal angle of attack is not all. There are several aspects in the flow, not only the angle of attack. It is quite complex, so I would no reject long fins completely. They may not be ideal for speed swimming, but may offer some advantages for slow swimmers. The long fin (if correctly designed) allows for more relaxed, steady / continuous kick with little turbulences. At the kick the pushing edge is only part of the time in the optimal attack angle - there are rather big "dead" motions bringing only little propulsion if you have a type of fin you described. In contrary, the long fin (together with your body), moves in a sinusoid, and propulses you smoother, and possibly more efficiently - there are really far too many factors involved to tell it without testing that long monofins are not well suited for freediving. In animal world you can finally also find both wide short and narrow long fins, and they seem to have withstand millions of years of evolution, so both probably have some advantage.

Well, I am not expert in hydrodynamics, but we have a university professor in fluids flow in our club, so I may try to get an expert view on the topics from him. We also discussed that he could propose his students some research jobs related to freediving and to swimming fins - they might try some software simulations of different types, shapes, and length of fins.

[Fondueset]

Trux, I agree with what you've said above. My thinking is that new technologies should be incorporated in a way that still keeps the emphasis on athletic performance - not by imposing an artificial limitation.

[Bill]

"the leading edge of the monofin is subjected to very disturbed and turbulent water"
That might be good since the front of all blades (mono and bi-fin) is trying to produce thrust in the opposite direction according to my flow model.
"have a "fin" at the end of a arced shaft that project out in front of the body"
That appears to be the best solution. Combine it with a thin symmetrical foil that is very stiff except for 20-30% at the trailing edge and we're on the same track. $75k is overkill, I figured less than $750 for mod 1, a total disaster, mod 2, to fix all the problems and mod 3 that might actually work, just like all new designs. The money is easy to find, it's the 3-400 hours of labor by a skilled model builder that is holding me back.
About rules. We don't need no stinking rules except to cover length, width, chemical assist, atomic power, etc., etc.

[Fondueset]

I am categorically opposed to the use of nuclear power in constant ballast.

[Erik]

Originally Posted by Fondueset

I am categorically opposed to the use of nuclear power in constant ballast.

Luddite!
j/k

[jome]

Well, I said maybe time to think about it, not time to enforce it. I don't want too much limitation either. But in F1 there is certainly thousands and thousands of pages of just restrictions on what you can and can not do.

Just an off the wall example. Is it currently banned by the rules to use an external power source on a monofin? I mean we would need to have at least some general guidelines on what is a fin and what is a scooter? Well ok, it is kind of obvious, no power sources. How about a contrapiton that has a propellor and you paddle it like a bi-cycle? Taking it really far - is Ted's "muscle powered submarine" allowed? It's constant in weight, it's muscle powered...

Is a "merman suit" a fin? I mean a suit with a trailing "fin" going all the way through the body (kind of like an eel). Or should "with fins" be restricted to "something that is attached to the feet". So is attaching to the knee ok?

I know I know, I already see it coming "we have enough rules already!"...I'm simply pointing out that currently there is pretty much no definition of what "with fins" actually means...And it's currently not a problem because everyone pretty much has the same type of fin - nothing else is available. But things might change in the future...

Well I hope at least someone catches on to the playful tone I'm intending to have in this post, but it's sometimes hard to express in writing

[BatRay]

Originally Posted by trux

Well, I just came back from the training where I asked Cedric Genin who also briefly tested the C4 monofin in Italy, and his comments were even much more negative. He did not like it at all. He did not even like the foot pockets - they may look cool, but do not seem to be well suited for the use on monofins. His comments were very negative and almost not publishable, but I realize that they were very subjective and based on only a very brief experience, without the chance to experiment with it and trying to find a more optimal kicking style.

Almost not publishable? Was his impression that negative? That amazes me that someone would be that violently opposed to a monofin

[Mullins]

I've also been known to swear a bit at products I don't like

[spaghetti]

Originally Posted by trux

Unlike what Spaghetti wrote, Cedric told me that C4 introduced the monofin as a finished product, not a prototype, and also mentioned price of some €600 (which might have been also a reason of his very critical view)
.

Absolutely not, this is very far from true. Of course I'm not accusing your friend of anything, it must have been a misunderstanding due to the linguistic gap (italians speak a horrible english and an even worse french).
The prototype was made just as a "demo" to display at the Apnea Training Conference wich took place one month ago at Lignano. There were 500 people in the attendance, freedivers and finswimmers of Italy and of the whole world: Stepanek was there, Kirk Krack, Coste, Mandy Rae, Musimu, Nitsch, everyone.
I guess that mister C4 thought it was a good occasion to show everyone that his company is actually working out a new monofin, and collect some feedback about this preliminary stage of the project.
Mister C4 said the prototype has been moulded on thursday, cut on friday morning, assembled on friday afternoon and brought to the convention on saturday. He says he had noticed that something went wrong in moulding the layers of carbon, and that the fin was "bending badly" (his words). But however...it's a prototype and it will take a long time, lots of testing and many modifications before the finished product will be available for sale.
..
If it was my company, I'd never made such a major error of communication strategy. As a consequence of the "demo" display, people are giving harsh comments about a product, the "C4 monofin" that doesn't actually exist yet: there's just a preliminary stage prototype. This is what we're commenting about.

[trux]

Originally Posted by spaghetti

Absolutely not, this is very far from true...

Yes, I believe you Spaghetti. I only interpreted what I heard from my friend, and I am well aware that he could be wrong (and am also not sure about the quality of his English), although he was pretty sure that the fin was a definitive product with a price already fixed - I explicitely asked him, because I knew from here it should not be so. And I also know that his opinion is very subjective.

I agree with you though that it was a mistake and a very bad strategy from C4, introducing to the public a fin that was completed just hours ago and (probably) never tested. Manufacturers usually test products with carefully selected testers who have to sign non-disclosure agreements and they definitely do not let any information leaking out unless they are already sure the product meets its expectancy.

[trux]

Originally Posted by BatRay

Almost not publishable? Was his impression that negative? That amazes me that someone would be that violently opposed to a monofin

He is not opposed to a monofin generally. He is a quite experienced monofin user (wing type monofin). He only did not like this one at all, and especially not the price tag set to it by C4. However, as Spago told, we need to wait with our judgments till the final product comes out.

[spaghetti]

Originally Posted by trux

I agree with you though that it was a mistake and a very bad strategy from C4, introducing to the public a fin that was completed just hours ago and (probably) never tested. Manufacturers usually test products with carefully selected testers who have to sign non-disclosure agreements and they definitely do not let any information leaking out unless they are already sure the product meets its expentancy.

Also C4 of course tests very carefully the products before selling them. But it seems their new "style" is to show off the prototypes even a long time before the finished product is completed and available for purchase.
They did the same with the C4 Urukay speargun. It's not yet available for purchase and still under testing, but the prototype was shown off 18 months ago at the annual meeting of an italian spearfishing community. Everyone who was at the meeting, could be you, me or Porky Pig, everyone of the attendance, had the chance to shoot the gun in the pool. And that was too a preliminary prototype, considered that after 18 months it's still under testing and development.
I don't think it's a smart policy: such a long gap of time could make people suspect that there's something wrong in the project.
On the other hand, C4 has such a strong reputation of quality and reliability, that probably they don't give 2 sh..ts of what people could prehemptively suspect...

[jome]

Well I will give C4 props for taking a bold step in another direction and actually trying out something new (well, in a way new, in a way, old - just merging 2 bifins )

Like I said, I did not personally find the thing very appealing, but that isn't to say it must be complete rubbish. With a different style and a little modifications, it might just work. Maybe not for all diving, but some.

I do like to see something new for once in a while. Also they have been very successful in creating a brand. Without any logos or stickers, there isn't one second doubt when you see the fin that it's a C4 product.

But since they obviously got the knowhow on how to work with carbon fiber, why not go more to the direction of the lunocet design?

[trux]

Originally Posted by jome

Well, I said maybe time to think about it, not time to enforce it. I don't want too much limitation either. But in F1 there is certainly thousands and thousands of pages of just restrictions on what you can and can not do...

Well, there certainly are some restrictions, mostly based on safety concerns, but I do not see any reason for introducing any restrictions in freediving propulsion. Aside from the obvious external power source of course.

As for fins and no-fins disciplines: at no-fins, no propulsion enhancements should be allowed (and I believe it is defined so in the rules too). That includes "mermaid" sleeves for the legs unless used only passively for reducing the drag, like in the case of Wes Lapp who did his no-fins record without leg propulsion. I think such definition is pretty good and working well now and very likely in future too. I expect that in future competitors will start using more and more diverse hydrodynamic suits, or possibly extensions changing their body shape. Personally, I do not see any problem with it, but would understand if some people would want to keep the discipline "clean" and natural - in that case some regulation or discipline splitting may come into discussion.

At disciplines with fins, I see no reason why competitors should not be allowed to use any type of human propulsion, including devices like the Aqueon, or propellers. If they are indeed superior to bi-fins or monofins, why sticking with inferior technology? Makes no sense to me. I would not impose any limitations. Well, maybe human powered submarines where the diver is encapsulated in a cockpit (though still operating it in apnea) should be excluded, but even here I am not sure if it is necessary.