Extreme Dolfinism

Spearo_the_Hero said:

...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...

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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?

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 said:

...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) ?

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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.

noa said:

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

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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 said:

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

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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.

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.