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Extreme Dolfinism G2

Discussion in 'Monofins' started by REVAN, Apr 30, 2014.

  1. Chipswim

    Chipswim Well-Known Member

    Local Time:
    3:39 AM
  2. REVAN

    REVAN The Right Stuff Supporter

    Local Time:
    2:39 AM
    Yes, the tuna and marlin have tails of hard bone and they are fairly rigid, but they do have a little spanwise flexibility. Between the two, I think the tuna is a far more attractive looking swimming machine. The sword allows to marlin to cheat and get it's food while not swimming as fast as the tuna.

    Did you take this picture at the tuna park, Baiyoke; or is it off the internet? It is a gorgeous picture of a tuna.

    It is interesting how the thickest part of the fish is half way back the length of the body. Hey Pete! I think this guy is more "Laminar" than you. I think you can tell the laminar from the non-laminar flow regions from the different color/texture of scales, front vs. back. It is very interesting.
     
    Last edited: Sep 4, 2014
  3. baiyoke

    baiyoke Well-Known Member

    Local Time:
    10:39 AM
    It is from the internet. I've seen a lot of Tuna pics lately, but when quickly googling "bluefin" in picture-setting yesterday this one caught my eye instantly. It's a Beauty...! You should put something like that on your web page.

    I think however it's shot a bit from the front, other pictures show the widest area about 1/3 from the front.

    I didn't attend the "diving with Tunas" for a number of reasons: 1) It wasn't part of the holiday plan 2) there are moral issues to holding them in a giant net like that and 3) it is said that the water is full of some kind of Tuna oil-like substance from the surface of the fish, and spending the holiday smelling like a tuna was not an option this time around :)

    REVAN I think it's obvious why you started out with the dolphin and orca reference, but if you ever need a name for a more specialized fin like the Orca 2.0 (or version 3.0) it could be: Blue-fin ;-)
     
  4. Fondueset

    Fondueset Carp Whisperer

    Local Time:
    5:39 AM
    Ichthys, I've been pondering what you mean by 'limitations unconsciously imposed'. I think one such limitation is the idea that an efficient fin must look like a dolphin or tuna tail. In the case of both the hyperfin and dol-fin, engineers analyzed HOW these tails work and based their designs on mathematical findings. The dol-fin in particular departs from romantic notions about how such propulsion should look and instead focuses on generating thrust and reducing drag based on an understanding of the laws that govern such propulsion and the materials being used. If anything this is overcoming the limitations to which you allude. Moreover, the performance of the fin supports the accuracy of understanding and execution in the design.

    I don't say there isn't something better - neither does Revan say his fin is the best - and there is always something better. But your statement about unconscious bias in design is not best supported by the Dol-fin series fins - which are almost unique in their reliance of an understanding of principal - as distinct from appearances.
     
    REVAN likes this.
  5. REVAN

    REVAN The Right Stuff Supporter

    Local Time:
    2:39 AM
    That is more like what I had expected. I looked at some other pictures and you are correct. The widest point is less than half way, and probably about 1/3 of the way back.
     
  6. REVAN

    REVAN The Right Stuff Supporter

    Local Time:
    2:39 AM
    It is only the best I know how to make at the moment. A new product needs to have a combination of viable attributes that will hold favor in the monofin market for 2 or more years, because that is about how long it usually takes to develop a mature replacement technology. But, it seems I'm always investigating new ideas. I test dozens of ideas/concepts each year. Few of those ideas actually make it into a production monofin.
     
    Chipswim likes this.
  7. Ichthys

    Ichthys Well-Known Member

    Local Time:
    5:39 AM
    Very impressive.

    Fondueset, that is certainly true that a lack of understanding or appreciation for the goal being pursued would be a limitation. What I meant was actually a little different, but I'd rather not criticize any further. Suffice to say I don't like the idea of a blade, but as it proves to be efficient I could warm up to the idea of putting one on my feet. :)

    I've been wanting to ask, have you guys ever tried breaching with the DOL-Fin?
     
  8. Fondueset

    Fondueset Carp Whisperer

    Local Time:
    5:39 AM
    I think the Dol-fin is more optimized for cruise. It might be possible to breach with it, but I'd not guess that would be it's cup of tea. The only clean breaches I've ever seen were with sprint stiffness hyperfins.
     
  9. Chipswim

    Chipswim Well-Known Member

    Local Time:
    3:39 AM
    As long as the fish are swimming 30 mph and we are swimming 3 mph there is work to do and no stone should be left unturned.

    So enjoy all the personalities and ideas represented in Deeper Blue!

    Convinced that Revan and Ted are amongst the precious few most likely to find the next break through AND build it AND offer the product to all of us patiently watching and waiting.

    Most of us continuously brainstorm what could let us swim better and faster... Effortlessly!???

    There is some evidence that propellers can work really well moving things through the water....

    The question becomes: How do we turn a propeller with human power while maintaining a streamlined body position?

    Consider the peristaltic motor I came up with and actually built pictured below. Yes! It is compact and designed to be driven by intestinal contractions! Genius! (I thought) PSS_Dripless_Seal.JPG m1Eo7KhkXgDayV8vFMU6yog.jpg

    As you can see in the photo of the completed device I then rigged it up to drive a propeller shaft! (The peristaltic motor is actually the wider part of the shaft as you can clearly see...) image012.gif

    Unfortunately ¡¡ When I got it inserted it was so horribly uncomfortable that I could barely use my intestinal contractions to spin the propeller at all ¡!¡

    Looks like we are back to Revan and Ted as our designers most likely to succeed !!! Rooting for them both!
     
    Last edited: Sep 4, 2014
  10. Fondueset

    Fondueset Carp Whisperer

    Local Time:
    5:39 AM
    In the Interest of Clarity: I am not a fanboy. I don't get free fins from Ron for testing his and if I thought they were crap I'd have sent them back to him and told him. I would not have bitched about them in forums unless I thought he was being dishonest.

    Nor do I think the Dol-fins are the absolute shit.

    I prefer my hyperfins. But my hyperfins are a bit unusual - they are made by Alex Lichenko at Starfins - they are soft - cruise- tuned fins and they are as comfy as a pair of bedroom slippers in temperate waters - this is extremely unusual for hyperfins. It's taken me years to find a fin builder that meets my criteria.

    So, in my testing of Ron's fins I am fairy careful to set aside my kinesthetic addiction to hyperfins. My criteria in testing are Cruise Efficiency, Comfort and durability. So far the three Dol-fins I've tested relative to my hyperfins go along about like this:

    Efficiency:

    X-20 - slightly less, Orca - very slightly less, Orca Gen2 - Probably slightly exceeds with wide blade.
    An important point here is that these three models were tested with three different blades. With the wide blade on all
    models I would expect improved performance.

    Comfort:

    All Models -Matches - Exceeds in winter when the slight compression of my hyperfins becomes a factor

    Durability: No Brainer

    I'll add portability - which is another win for the Dol-fins - particularly the X20.
     
    PoseidonSv likes this.
  11. Ted Ciamillo

    Ted Ciamillo BANNED BANNED

    Local Time:
    5:39 AM
    Dammit Chip, you weren't supposed to reveal this yet. I thought we had a deal... you also said it felt great during testing; why are you changing your story?
     
    neurodoc and Chipswim like this.
  12. REVAN

    REVAN The Right Stuff Supporter

    Local Time:
    2:39 AM
    There is no magic to be had in a monofin. It cannot violate the laws of physics just because it looks different or cool. When operating on design point, hyperfins are already near the physical limits for propulsive efficiency, so we should not expect any new fin design to produce dramatic performance increases, beyond that of a good hyperfin. In my opinion, achieving large improvements in performance will require more than just a new monofin. If we want to actually swim like a dolphin, we will probably have to find a way to look more like a dolphin (at least in a hydrodynamic sense).

    It is great that your Starfin has such a uniquely good fit, because it provides a benchmark to strive to exceed. Most hyperfins are uncomfortable; some are extremely uncomfortable. I've never used one without getting blisters, and sometimes it only takes about 10 minutes of use to start peeling skin. From a market perspective, it is not good enough to be able to find a comfortable monofin with years of trial and error and multiple fin purchases. This has been a bane for freedivers ever since they started using hyperfins. The result has been that many freedivers simply don't use hyperfins. They never find out how much more fun can be had when dives are efficient, easy and long. This reduced scope of high performance monofin use limits growth in the sport.

    Comfort and a proper fit must be made available on the first purchase, not the second or third. Comfort, durability, portability - these are the areas where we can expect to see large improvements from new types of hardware.
     
  13. Fondueset

    Fondueset Carp Whisperer

    Local Time:
    5:39 AM
    Absolutely agreed! I've had hyperfins that I had to use with silicone grease on my blisters. After 20 minutes the pain was so intense I could no longer focus on technique and, when I took the fins off, there was blood in the water.

    I just wanted to clear up my position based on some communications I've received. I approach testing with a definite bias toward my personal status quo and I will never recommend anything I don't think is excellent. The Dol-fins are excellent and I highly recommend them. As I've said before - from my perspective they are definitely off probation.
     
  14. noa

    noa Well-Known Member

    Local Time:
    10:39 AM
    This question might be slightly unrelated, but it somewhat baffles me how after all this time hyperfins remain so uncomfortable ? There are so many other solutions such as cycling shoes (and others) that I fail to understand why these old materials and methods persist...
     
    Chipswim likes this.
  15. Fondueset

    Fondueset Carp Whisperer

    Local Time:
    5:39 AM
    Traditional hyperfins are built for pool competition. Fins built for speed are stiff and require a tight fit to be efficient. Same is true if you are doing depth. (beyond 70m or so). In dynamic I think even if the foot pocket slips a little - it still contributes to thrust.

    (I should also add that my Tropol fin is quite comfy - though not quite as so as the Starfins. It is however a very heavy fin, with a stiff blade. Still, I did my deepest dive with it and didn't even know it was there.)
     
  16. Kars

    Kars Well-Known Member

    Local Time:
    11:39 AM
    Quick tip for anyone who gets blisters in their rubber foot-pockets: insert you foot in a piece of thicker plastic (old bag), slide in with a bit soap. It is true that standard rubber monofin pockets are tight, even so tight that people can only endure them for 15 minutes. The reason is that a tighter pocket has a better power to blade transfer. Monofin sprinters do not care about comfort, they prefer performance. Freedivers, who like to spend hours in the open waters and pools, need comfort.
    Manufacturing rubber foot pockets is a skill. If the pocket is exact to the foot side, the rubber can be very stiff, reducing play and foot pressure.

    Fondue, I like your reporting very much. It sounds like the new design may finally outperform the hyperfin in the performance department.
    Is there a full review in the works Fondue?
     
  17. Fondueset

    Fondueset Carp Whisperer

    Local Time:
    5:39 AM
    Hi Kars, I've not been able to do the kind of comparison I did with the Orca and smaller blade an videos - but it is something I am working on. (changes in pool staff) Per your remarks - I think in dynamic the heel strap on a slightly loose foot pocket can make up for looseness and contribute energy storage/thrust because of the relatively low load in dynamic - just theory at this point.
     
  18. divebike

    divebike Active Member

    Local Time:
    7:39 PM
    It's not a romantic notion of how things should look as to why I think the ultimate fin is probably more like a tuna fin, evolution weeds out such silliness, its people that come up with crap, I've read 2 different research studies that have found their fins to be an improvement on any naca foil, I don't have a link to them as I viewed them a couple of years ago. I don't think biomimicry is the be all end all , you'd be mad to look at a cheetah for example and try and devise a way to run like them, you just get on a bike. We are trying to use a fin the same as they do, by oscillating it, the main difference being the speed by which they move both the fin and themselves, which could possibly make them not the ideal fin after all, but no one has shown this to be the case, it's mere speculation.
     
    Mukiker likes this.
  19. Fondueset

    Fondueset Carp Whisperer

    Local Time:
    5:39 AM
    Does the ultimate human then look like a tuna?
     
  20. Ichthys

    Ichthys Well-Known Member

    Local Time:
    5:39 AM
    Are we talking facial resemblance or body shape? ;)