Extreme Dolfinism

[REVAN]

...I am noticing the lack of velcro on the top side of the strap is allowign the whole strap an excuse come unloosed and this happend on one dive...

I’m still having trouble understanding why you are having this problem. I have a set of binding straps that I’ve been using for about 8 years and on countless dives both in the pool and in the ocean. They are getting very worn out now and probably have less than half the Velcro’s original holding strength, but it has not once slipped or come loose on me. I only have two ideas as to why your straps may have slipped.

1) The straps are way too small and the top flap with the loop fastener is not wrapping around the side of your foot and fully engaging the hook fastener. If this is the case, you can try using a thinner dive sock (something without a sole or only a very thin sole) that will reduce the thickness of your foot where the strap loops around it. This would leave more slack for better engaging the Velcro. The other option would be to switch to using a medium strap instead of the small.

2) The Velcro has become contaminated with something that is preventing it from hooking up properly. Is the Velcro clogged with sand or any other foreign substance? If so, can you clean it out and see if that corrects the issue?

If it is not either of these, do you have any other ideas as to why your experience with the Velcro may be so different from mine?

 

[Spearo_the_Hero]

Hello Ron...well i must say that the DolFin Classics that I have are Awesome! Been diving with them daily now and love them. Best part is they don't lose effectiveness at depth so i can kick with relative calm unlike bifins that 'give in' to deeper pressure. Since I always dive alone, i've only taken these down to about 35 or 40M and love how i can kick the same as I would if I was only at 20M for the ascent and save energy from having to kick hard at the turn.

The straps are fine by the way...just need to strap 'em tight.

 

[Mullins]

they don't lose effectiveness at depth so i can kick with relative calm unlike bifins that 'give in' to deeper pressure.

Are your bifins made of foam?

Also, 35-40m solo isn't a good idea. Even I don't do it, and it represents about a third of my PB.

 

[Spearo_the_Hero]

Are your bifins made of foam?

Also, 35-40m solo isn't a good idea. Even I don't do it, and it represents about a third of my PB.

:rcard Yes foam fins....hard to get down but faster to come up. I wast thinkin change my screen name here to Foam_Boy

:rcard Ok so I finally took out my bi fins after dusting them off from being with the Dolfins for so long. Turns out I can also as easily go down to 30M+ as with the DOLs and come up just about with the same speed and relaxation....so now..i'm thinking....Well, I was wrong to suggest that previously my bi fins were harder to come up with deeper than 30M...it is not the case now perhaps because I am much more accustomed to the depth and with less fear. So, I will have to test the DOLs at a maximum depth of 50m+ when I dive with a buddy and line set up.

Thanks for calling me a foam boy, which allowed me to get out the bifins and test them out again. My conclusion now is I can get down to 30+ about the same with the bifins and come up just a tad faster with the DOLs, but perhaps not as relaxed.

 

[Spearo_the_Hero]

DolFIN classics are nice...here's a quick dive with them: http://static.ak.fbcdn.net/rsrc.php/v1/yf/r/wn29KX6UvhD.swf?v=10150099126861816&ev=0

 

[Fondueset]

STH - perhaps your earlier impression was just from the change of weight at depth when you are wearing suit, weights etc. I know that when I was using my Ice fins in the dead of winter - with a 6 mil suit and weights - they felt very weak much below 20 meters.

 

[REVAN]

It is high time for another update. A lot of busy work has been happening the past several months, but it is finally starting to actually feel like things are starting to move again.

First off, I have updated the website. Development news and sales information can be seen at:
DOL-Fin Retail Sales Publication

Special sales promotions and updates can be found on Smith Aerospace Corp’s new Facebook Wall:
Smith Aerospace Corp: DOL-Fin Monofins | Facebook

DOL-Fin Orca SN#0001 was completed and shipped out to its new owner in late February. I’m told that it is has just recently departed for Dean’s Blue Hole, where the owner/athlete is preparing to compete in the Vertical Blue competition with it. There has been extremely little time for him to prepare and train to learn how to utilize this unique monofin. It functions so differently from other monofins that new techniques will need to be discovered, learned and refined to maximize the fin’s capabilities. It may take many months or possibly even years to truly hone those skills and techniques. None the less, it will be very interesting to see what he can accomplish with the DOL-Fin in the few training days available before VB kicks off on April 8th.

Cheers,
Ron Evan Smith

 

[noa]

Hi Ron,
great to hear the fins are finally available !
you explain that someone would need quite some time until he can get used to your fins and start to get some real benefits from them. so, when someone wants to buy and start using a Dolfin, what would be the best way to learn how to properly use it (besides of course spending a lot of time in the water) ?
one more perhaps odd question. i believ that the Orca model would be too advanced for my skill level and i'm thinking of an HP. having said that, i believe that the single blade/footpockets attachment point of the Orca must be a fair bit more hydrodynamic than the twin attachment of the HP.
so, this brings the following question. would it be possible to put together an Orca blade with an HP style footpocket (basicly, open structure/no fairing) ?
thanks for any suggestions.
all the best...

 

[REVAN]

...when someone wants to buy and start using a Dolfin, what would be the best way to learn how to properly use it (besides of course spending a lot of time in the water) ?

Obviously, the best solution would be too train with someone who is already proficient or with a training academy skilled with the DOL-Fin products. However, it may be years before anyone is offering such a class. In the mean time, I've started a DB forum thread dedicated to DOL-Fin training and information sharing. I will be doing what I can to help divers through their learning curve and if the communications are publicly available, they could potentially help many to learn. I've already made a couple of short videos that, I hope, can help some newbies with the basics. More is definitely needed, but should come with time, and I'm hoping that customers will also be adding useful tips and content as they learn new techniques. Here is a link to the thread: http://forums.deeperblue.com/monofins/88471-dol-fin-information-exchange.html

Also, I should mention that it is useful to dive with me if you can get the chance. At present, I am the worlds most experienced DOL-Fin user for both scuba diving and freediving applications. I periodically get out of the shop for some diving and enjoy meeting with other divers. I will be in Florida and also Puerto Rico in May. If anyone wants to get together for some diving in either of these locations, let me know and we can try to coordinate a schedule.

...would it be possible to put together an Orca blade with an HP style footpocket (basicly, open structure/no fairing) ?

To some extent, that is basically what the HP is. From a performance/efficiency perspective, if the water's flow around the foot-plate is not going to be closed behind it through the use of streamlining (i.e. - the Orca fin's fairing), then there is really no benefit to the narrow fin attachment exhibited on the Orca. Of course, the HP is not quite the same as a DOL-Fin Orca, even though it uses the same foil and fin tips. The HP has a different balance of characteristic dimensions (span, fin area, lever arm...) that gives it a wider set of possible diving applications, whereas the DOL-Fin Orca is optimized just for freediving. From an overall market perspective, this is a good thing, but for someone who is dedicated to only freediving, a different balance could add another 3 or 5% performance under operating certain conditions.

FYI: I have one fin like that presently for sale at:
Smith Aerospace Corp: DOL-Fin Monofins | Facebook

This EXPERIMENTAL fin is basically a DOL-Fin Orca without the streamline fairing. Alternatively, you can think of it as a DOL-Fin HP that has been morphed to have the same characteristic dimensions of the Orca. It was an engineering asset I built for developing the DOL-Fin Orca. You can actually see this fin being used in various stages of development and configurations in some of the videos I have posted on the 'smithaerospace' Youtube page. Now that the Orca's development is done, I don't really have much use for this fin anymore. But, it is still a really good solid fin that someone could get a lot of use from, so I decided to sell this EXPERIMENTAL fin to test out using Facebook as an auction tool and work out problems with the auction/sales process before getting to the actual Orca sales.

Please note that there is only one of these fins for sale. Unless the auction shows a demand for it that is much higher than I am anticipating, I have no plans to build any more fins like this one.

Ron

 

[noa]

Hi Ron,
Thanks a lot for your long reply full of great info.
Maybe at some point in time you could organise and facilitate a Dolfin instructor training in order to get a first batch of instructors specialised in the dolphin swimming techniques. They could then go out and start teaching all the people who have or want to buy Dolfins.
I did go to your facebook page and saw the experimental fin you're selling. It looks interesting indeed but I think that I would probably go for an HP as it is a more finished and smooth product ( especially the footpocket area). Would this experimental fin have a big performance advantage over an HP in constant weight ?
Thanks again...
Posted via Mobile Device

 

[REVAN]

Would this experimental fin have a big performance advantage over an HP in constant weight ?Posted via Mobile Device

Eight or nine months ago, I would have said yes. But I have been making improvements to the HP that have been closing this performance gap (I think). I'll be able to report more knowledgeably on this after my diving trip in May. The main purpose for this trip is to really put the HP through its paces. According to pool data the HP is now within 5% of the experimental fin, but I have yet to get the newly refined design out into deep water to use it for any depth diving.

My personal impression is that the HP is becoming a pretty sweet monofin. I've been finding and implementing the refinements needed to get the performance up and it is extremely versatile in its capabilities. I think it makes a great freediving fin, and it can do things for scuba diving that are almost unbelievable (swimming tech in the scuba industry has been so crude that there was a lot of potential to be had). The HP is lightweight, and folds up to fit in a 36 inch bag without any disassembly. I'm using this bag on my trip and the HP fits in it perfectly: High Sierra A.T. Gear 36" Drop-Bottomed Wheeled Duffel - eBags.com. I think this is going to make a great gear bag and travel bag for use with the DOL-Fin HP.

The experimental fin will fit in a more typical large suitcase that is only 30 inches long. However, like the DOL-Fin Orca the fin blade needs to come off to fit it in (about a 4 minute job). The main difference is that the experimental fin is going to have a similar feel to the Orca fin in terms of foot-loads/resistance, distance per stroke and cadence. These are things that make the fin feel more familiar to freedivers and are therefore somewhat comforting. It also can go a little bit faster than the HP because it is tuned for faster swimming speeds. This speed difference could be significant to CWT diving, I don't yet know. The experimental fin may get you up through the negative phase faster which saves the energy of fighting negative buoyancy for longer durations; but it is not that much faster, and the HP pushes more water for better efficiency when fighting resistive loads (something very useful for someone dragging along scuba equipment). I don't know how these two opposing differences are going to play out yet.

 

[noa]

Great info. I guess, like always it's a game of compromises, lose some, gain some. All in all I imagine the HP will make a great intro fin into the Dolfin style monofins for freediving.
Is it already available for purchase or are you still tweaking it before production ?
Posted via Mobile Device

 

[REVAN]

All done tweaking: The development all happens in the pool. That is the best environment for being able to measure performance losses and gains for making design choices, and that work is all done now. The only thing left is to take the HP out into OW and make some promotional videos with it.

 

[Kars]

Hi Revan,

Could you please also try a 16x50m swim and a 50 and 100m apnea sprint?
I would love to see some slow motion footage of the fin and diver performing at various speeds. It would also give me some insight how to use the fin. A comparison side by side with a traditional hyperfin model would be extremely cool, but that video review would be something a 3rd party may want to pick up.

Listening to my subconscious feelings I still feel I first need to try and test it before I can believe such a small surface area fin would offer me the same or better propulsion and feeling of safety and security that a traditional fin does. To my eyes a hyperfin model looks much more like a natural fin, something "evolutionary right", so as a human being I need to overcome this programming/sensation. At the same time in this age of marketing I've seen a lot of 'high-tech' stuff hyped up over the hill performing not as advertised. So there are some forces that work on me against believing in such a radical looking product. On the other hand your very patient, candid, forthcoming, modest, thorough approach does give me confidence that your fin is going to come through and indeed offer a new branch of monofins that bring value and deserve a place in the underwater world.

So I'm really looking forward to seeing some cool HD video's can study and testing out one of your fins.

Love, Courage and Water,

Kars

 

[noa]

Good points Kars. I know what you mean about wanting to see some more facts before taking the plunge. It does appear however that Ron is honestly and openly standing behind his words, without being afraid to go back to the drawing board when needed.
In the end the only way to see how well these fins work will be to try them and give the whole process some time. I certainly hope and believe that they will end up walking the walk and not just talking the talk.
Posted via Mobile Device

 

[trux]

BTW, Kars, have a look at the tails of tuna fish (one of the fastest swimmers among fishes). They are tiny and slim. The ratio of the square area of their tails and their body size is quite small in comparison to other fish, and the form is pretty close to the hydrofoil used at DOLfin. So you cannot really claim that Ron's development denies the evolution.

 

[Kars]

You're right Ivo, smaller ratio to the square is a fin design working for faster speeds.
But at the same time we freedivers are not flying through the water like tuna, especially at depth where we start from 0 and try to make some speed against some kg's of negative buoyancy in the dense water matter.
Maybe I should say the instead of view of evolution, my programming.
In a way it mimics the aviation development, where slow planes had thick and broad and lengthy wings, and todays' fighters have thin, short wings.

So I'm looking forward of hearing some 100m CWT report and video too

But maybe Ron could provide us already some drag number comparison? I suspect his design has a good edge over the hyperfin design, providing superior glide abilities.

 

[trux]

The problem of an elastic fin, like the classic monofin, is that at every moment only a very small portion of it is in the ideal angle of attack, so actually only a fraction of it is used for the propulsion, while the rest induces a lot of drag. In contrary, at a hydrofoil the entire blade is in the angle of attack, and the entire square area of the blade works. So from this point of view I think the DOLfin has a bigger working area than a classical monofin. Additionally, the high width/length ratio causes much less induced drag.

 

[Bill]

'The problem of an elastic fin, like the classic monofin, is that at every moment only a very small portion of it is in the ideal angle of attack, so actually only a fraction of it is used for the propulsion, while the rest induces a lot of drag.'
TNX for the statement Ivan. I have had many discussions on this subject and found very few divers to agree with this. Now I can quote you along with Ron.

 

[cdavis]

Pardon my ignorance, but does the HP change the blades angle of attack through the leg stroke or between up and down strokes? The Aqueon does, but I don't see any evidence in the pics that the HP does.

Connor