Extreme Dolfinism G2

[REVAN]

Actually, I think it would be worthwhile to combine it with a freedive-related event. Take a couple of fins, which can be used/tried by the community. It's your target audience, after all. And it's good to get feedback from a broader base, not only from the elite, but also from people who simply enjoy water and love the general vibe. This way, you could collect footage, testimonials and probably even sell one or the other testing fin at a "promotional price". Above all, people can try these fins, gain confidence in the tech, and spread the word. [emoji1] Thanks to your design, all it takes is a suitcase, a couple of blades and several cycling shoes of different sizes to provide a fin for almost anyone [emoji16]

This is basically what I did with the X-20 when it first came out. I took it to Hawaii in the weeks before the 2012 US Nationals and let anyone use them who wanted to. One Australian diver's WW Glide didn't survive the airlines, and used an X-20 or Orca for about a week until the local fin doctor repaired his cracked fin blade. A lot of other divers tried it out of curiosity. The final outcome was that many of the local Kona divers bought X-20s from me. There are at least a half dozen DOL-Fins in and around Kona now. The problem is they all still have their DOL-Fins and those monofins aren't going to wear out any time soon. So, that particular market is kinda saturated regarding DOL-Fin products at the moment. I don't know of other good events where this type of thing could be easily repeated without traveling internationally, which gets too expensive to be cost effective.

 

[PoseidonSv]

Recieved my DOL-FIN Pilot and managed to build it together without any problem using my SIDI bike shoes with it.

 

[REVAN]

USPS has been getting some bad coverage lately from various accusations posted on DB forums. I usually ship USPS, so this situation impacts my business. In case these accusations are causing anyone is questioning whether it is a bad idea to order a DOL-Fin shipped by USPS, I wanted to provide a little background information to add some clarity on the subject.

I have found USPS to be fairly reliable. So far, I have not had any packages actually go missing (knock-on-wood). The one drawback I've been warned of is that IF something does happen and a package is lost, USPS can be quite slow to respond to a loss claim. The USPS will not reimburse for a lost package until they have completed their investigation, which usually takes a month from the time it is reported and requested. If a month passes before an inquiry is launched, it will be another month before it is resolved.

That said, there must be a record of a package before it can be declared missing. And there are many places where that record is tracked and recorded.

This is an X-20 presently en route to Surrey. It has not been delivered yet, but as can be seen there are plenty of nodes where a package will be scanned and tracked when shipping via USPS. Tracking even happens outside the US as it passes through customs and up through delivery. This package has been en route for about a week now, and is nearly at it's destination.

I've had some shipments to SE Asia take as much as 21 days for delivery. But most deliveries are usually much faster than that. For comparison, this is the last shipment I made to Australia. This one was even faster than predicted at only 6 days (international date line crossing adds a day) with PMI service (that's the economy rate).

I have seen cases where a tracking scan is delayed due to network problems. I had no track feedback from one package until it got to the LA sorting facility a couple days after I dropped it off. A few days later, it finally showed the local scans from Sahuarita and Tucson that happened first.

While it is possible for some tracking scans to be missed, it is very unlikely for all of them to be missed, and that condition is unprecedented in all my experiences.

The bottom line is that USPS shipping is a good a reasonable way to ship products worldwide. USPS does not have the excellent customer service of UPS or FedEx, but it is a lot less expensive and it still gets the job done; and with the latest shipping agreements, a USPS package is usually on the FedEx jet when flying overseas anyway.

IMO: USPS shipping is OK.

 

[Philip Fennell]

USPS has been getting some bad coverage lately from various unsubstantiated accusations posted on DB forums. I usually ship USPS, so in case anyone is questioning whether it is a bad idea to have their DOL-Fin shipped by USPS, I wanted to provide a little background information to add some clarity on the subject.

I have found USPS to be fairly reliable. So far, I have not had any packages actually go missing (knock-on-wood). The one drawback I've been warned of is that IF something does happen and a package is lost, USPS can be quite slow to respond to a loss claim. The USPS will not reimburse for a lost package until they have completed their investigation, which usually takes a month from the time it is reported and requested. If a month passes before an inquiry is launched, it will be another month before it is resolved.

That said, there must be a record of a package before it can be declared missing. And there are many places where that record is tracked and recorded.

This is an X-20 presently en route to Surrey. It has not been delivered yet, but as can be seen there are plenty of nodes where a package will be scanned and tracked when shipping via USPS. Tracking even happens outside the US as it passes through customs and up through delivery. This package has been en route for about a week now, and is nearly at it's destination.

View attachment 40373

I've had some shipments to SE Asia take as much as 21 days for delivery. But most deliveries are usually much faster than that. For comparison, this is the last shipment I made to Australia. This one was even faster than predicted at only 6 days (international date line crossing adds a day) with PMI service (that's the economy rate).

View attachment 40374

I have seen cases where a tracking scan is delayed due to network problems. I had no track feedback from one package until it got to the LA sorting facility a couple days after I dropped it off. A few days later, it finally showed the local scans from Sahuarita and Tucson that happened first.

While it is possible for some tracking scans to be missed, it is very unlikely for all of them to be missed, and that condition is unprecedented in all my experiences.

The bottom line is that USPS shipping is a good a reasonable way to ship products worldwide. USPS does not have the excellent customer service of UPS or FedEx, but it is a lot less expensive and it still gets the job done; and with the latest shipping agreements, a USPS package is usually on the FedEx jet when flying overseas anyway.

IMO: USPS shipping is OK.

With regard to my recent experience with Ron's use of USPS, for my Pilot2, they have done the job and the parcel is due for delivery tomorrow. Tracking info from the start and none of this pre-shipment notification business. The parcel made good time across the U.S. and the Atlantic then dawdled through UK Customs but info all the way. Thanks Ron.

 

[Ichthys]

Much respect, Revan. That's something that needed to be set straight.

 

[HydroApprentice]

Same here, good service and coverage from beginning to end [emoji4]

 

[REVAN]

This video was shot back in late 2013, but it is finally up on youtube now. It is a nicely done video that shows just how versatile the DOL-Fin hydrofoil system can be for all kinds of diving applications.

 

[baiyoke]

What is that first fin in the video. Looks nice. Was it a prototype for a cheaper Orca-style (as I vagely remember)?

By the way here's a vid of a very rough prototype of an elbow support. From facebok

"
This prototype - a first and simple one - turned out to be too rough and simple. It's only real purpose was to let me relax my shoulders wich is a huge factor for me despite stretching, secondary it can add streamling and weight/inertia. However it made too much drag, so it was only on par to not using it, plus the added stress from handling a new gear, so didn't use it in competition despite judges kind approval. Turns are easy even the first time, in the vid I just came too close to the wall and didn't want to scratch it"

 

[REVAN]

I have tried something very similar, and many other ideas as well. As unstreamlined as we are in the water, it is perplexing that it is proving to be so hard to actually reduce our drag. I keep running into your situation, that the end result is not better than using no streamlining at all. Often the streamlining devices have a negative effect and actually make the drag worse instead of better. However, I keep experimenting, and I'll let you know if I find something that actually works.

It's good to know that the AIDA judges approved such a device for use in a competition, and kudos for your efforts. Which judges were officiating?

 

[baiyoke]

Judges were all from Denmark. I had been preparing them for two days, and also made a last minute thread on the AIDA facebok page. Technical board member (as I remember it) Antero Joki approved "that kind of things" and that made the judges open for an inspection on competition day:
https://www.facebook.com/groups/aida.freediving/permalink/10152552419427202/
https://www.facebook.com/groups/aida.freediving/permalink/10152552419427202/

 

[cdavis]

Drag issues are a big deal for my kind of diving. One of the things that makes the Dol-fin so nice is the minimal drag of the foil. If you watch the vid above, you can see the foil pivot slightly (in the center of the range where there is no resistance to pivoting) to line up with the water flow and minimize drag during the glide phase. The diver doesn't have to think about it. Anything else, bifins, or other monos, including the Lunacet, creates substantial drag during glide unless the diver works at lining up the fin with the water flow.

 

[REVAN]

What is that first fin in the video. Looks nice. Was it a prototype for a cheaper Orca-style (as I vagely remember)?

The working name for the fin the freediver was using was the X-22. It was a buoyant fin design. In the end, I used construction and flotation principles from that design in the Orca2, but decided not to market the X-22 itself. I needed my recreational design to be less expensive, and that was more important achieving optimum buoyancy. The result of that decision is the Pilot and Pilot2 models.

Most of the people who care enough about the buoyancy of a fin to pay for the upgrade to get it right, are advanced enough divers that they will also want the streamlining of the Orca2 as well. The X-22 just seemed to be in a middle ground that didn't have a big enough market to go into production.

However, if anyone in that small middle-ground market wants an X-22, I still have my prototype that I'll sell. It is in excellent shape. $750 with new shoes attached in a size of your choice (as long as I have it in stock).

 

[cdavis]

Ron, what is the float made of? what does it weigh? Is the fin exactly neutral?

 

[REVAN]

The float is a vinyl coated wood, strong and non compressing with depth. I think the fin weighed in at about 6 to 6.5 pounds dry, and is slightly positive in buoyancy (maybe about 1/4 pound).

 

[HydroApprentice]

I'm still completely blown away by the capabilities of the X-20, which is supposed to be the "recreational" model [emoji16]. However, the negative buoyancy is still something I need to get used to.

Does anyone have a suggestion on how to adjust the duck diving technique for a negative fin, so that the initial dive can be more relaxed, smooth and efficient?

 

[baiyoke]

I haven't noticed it - or can't remember it - to be significant when duckdiving. But a tiny undulation and move forward is what I do. Brings the fin up a bit, and gives you (a little bit) speed to cut down into the water (basic I know, but just saying that works for me).

The above is done with a neckweigth and no belt. If using belt only... hmmm.... perhaps buy some thicker and more buyant pants But then you need more weight... and the you need thicker pants again... Go for the neckweight I'd say

 

[HydroApprentice]

Thanks baiyoke, the neck weight might be just the solution to get the dive right. Indeed, 7 kg on a belt (5 mm suit) does not provide the best starting position to keep the fin up!
The ankle flick or small undulation before the dive was also my way to go, but it also takes me a bit out of "the zone" in terms of relaxation.

 

[baiyoke]

7 kg is a bit The problem is the position relative to the lungs. If you don't wan't a 7kg jaw-crusher neckweight, you could try with a 3kg neck + 4 kg belt. Or perhaps 4 neck+ 3 belt. OR you could use a weight vest if diving recreational, to place everything around the lungs

A neckweight will bring the fin up a ittle bit though.

 

[baiyoke]

Actually when I think of it, with all that neoprene in your lower body, a neutral distribution by a vest or an allmost neutral 3 neck + 4 belt should make your fin jump out of the water by itself

 

[REVAN]

Put 2 to 3 kg in a neck weight. That will get your trim about right. Put the rest of what you need on your belt. That is the weight that counteracts the wetsuit, which is fairly evenly distributed over you body, so you want that weight to be centrally located. Personally, I'd shoot for the 3+4 option, or maybe 2.5+ 4.5.