Fins and manoeuvrability

[danvolker]

1. Kick shape is a huge factor, almost never considered in fin discussions. Many fins have their own unique, "Best" kick shape, for the fins to work optimally.
2. Some of the kick shapes optimal for various fins, utilize muscles and leg leverage that some divers are optimized for by leg length and muscle training, others work parts of some key muscles that many divers have done little training in, and so won't do well with.
3. Some kick shapes force some divers, to use muscles they will never train effectively enough to be efficient with these kick shapes. The kick shape for the ScubaPro jet fin for Flutter kick comes to mind --the only kick shapes for flutter that work, do not use the existing muscle training well. This includes runners and cyclists, as well as walkers.
4. With a higher tech design, a diver would use much less of their un-trained muscles, and more of their well trained muscles, so that even just beginning with the fin, the diver can leverage the design of this optimal fin propulsion well.
5. With this same higher tech design, ideally the muscles used will not be the muscles that use up the most O2 from the blood stream....but they will be muscles that utilize enough leverage, to generate even more power than would be possible in traditional fin design....
6. Here is THE EXAMPLE of kicking shape and which muscles are used, tied to a fin system that leverages the power in a diver much better than the classic SP Jetfin....

[video=youtube;aAxmFOLM3Ak]https://www.youtube.com/watch?v=aAxmFOLM3Ak&[/video]

**Note....Of course you can't frog kick with these, but the fin shape and leverage and muscles used, are very well illustrated.
See the kick shape, and see which muscles he is actually using....The quads are used very little....it is more of an oscillation of your spine, hips, a little hamstring and calves....ulitmately muscles that don't blow much O2 from the blood in the speeds you see in the video....Ron is lazily cruising along, almost sleeping, and you see him swimming past scuba divers as if they were rocks on the bottom ** Think Dolphins swimming by divers....Do you think they might be more efficient at moving around in the water than scuba divers? Do you think they might be capable of precise control also? They have evolution....we have stagnated technology for fins in the last 80 years or so, but maybe we can start moving it forward again!

Ron swims much faster than a freediver with freediving fins, without effort, due to better technology.
He is also developing a hi tech set of bi fins...which I have tried before....They are not as fast and efficient as his DOl-Fin mono fin, but far better than scuba fins....and they approach DiveR Freedive fins without anything close to the length....AND, they frog kick well. They employ radically different technologies than the technology of traditional scuba fins.
Interestingly, Ron checked out my Excellerating Force Fins when he was diving with me for this video, and was blown away by how technologically superior they were to traditional fins like jet.
For the near future, Ron Smith's fins are for the people that want to buy a Ferrari or Lamborghini of fins...However, this is a new kind of fin technology that is likely to bleed off into some of the bigger mfg.'s if they see that divers in larger numbers, actually care about fin performance.....If divers would stop saying that all fins are equal

I also have another video of Ron using this Dol-Fin with a scuba tank on, and it the efficiency for a scuba diver is amazing.

 

[gkrane]

That contraption he has on his legs looks like a death trap.

 

[TN Traveler]

Scubadada - I would agree, FF Pros would not fit your style of diving. They are comparable in performance to a pair of Apollos or other high end split. They do offer the advantage of the FF foot pocket which is much easier on the legs/ankles and will allow you to swim with a much lower effort for longer distances. They are not for any type of technical diving.

I personally am still able to dive because of the FF foot pocket since I have damaged ankles, knees and a hip that just got too painful to dive with before I found Force Fins. I have several pairs, mostly that I have evolved into from my original PROs. As I found out about the different styles and materials, I started to realize that some of these might offer advantages and the more I tried, the more I found the performance advantages of the different models/materials.
The Tan Delta material offers superior performance mainly when you have to swim hard - it allows you to swim at a faster pace (or into a current) with less work than other materials. The design of the Excellerating Force Fin definitely maximizes the performance. My personal favorite is the Hockey Fin - not because it can outperform the others but because it is a different "Tan Delta" material that is easier to kick because of the loading characteristics - plus it was designed to provide maximum acceleration while using less energy for sustained kicking. They also frog kick well.

Just so you don't think I think Force Fins are the only fins to use - my wife normally dives with a pair of TUSA Splits - we just know that they have to be replaced every 2 year - because she hates booties and prefers a full foot fin. She has a pair of Excellerating FFs that she uses only for shore diving in Bonaire and when we do the wrecks in Key Largo (she found out that the splits don't cut it when the current kicks up). I have no problem with her choice.

Just to put things in perspective. Bob Evans signs and numbers every pair of fins made with the Tan Delta Material. He has produced these fins for about 15 years (none in the past 2-3). As of right now, Bob is hoping to begin producing Tan Delta fins in the next year, since he now has a new facility where he can directly oversee the production and continue to produce experimental fins.
I did a little checking with some of the other divers that use Tan Delta FFs and have figured out about how many have been produced.

Excellerating FFs - 225 - $700-$800
Extra FFs - 150 - $600-$700
Flying FFs - 120 - $600
Originals - 100 - $500
Hockey - 75 - $400

Total Tan Delta Fins - 670 - or about 45 per year. This is not a major source of income or profit for Force Fins - these are strictly produced for those that find that the added performance (defined as each individual sees fit) worth the cost.

So, it is no loss to Force Fin if you don't feel they are worth the price - no one is "selling" these for the company. Those of us that are proponents of the fins are trying to do nothing more than share our experience and offer up what we see as a better fin.

 

[danvolker]

That contraption he has on his legs looks like a death trap.

To freedive with it, it is better to learn how at the BHB first. The kick shape is nothing like normal fins or freedive fins. You have to learn an entirely different coordination for this.
It took me about 30 minutes to get this down well, and then you really progress well from there on.
It does help to be good at breath hold, when you are putting them on...or to have a float you could be hanging on to if your were concerned.
For that matter, you could tow a riffe or omer torpedo float, so if you ever were concerned with the surface and breathing, you would always have your torpedo with it's 150 pounds of lift or so

Personally, after the first 30 minutes, I would have felt comfortable swimming these out from the beach to 2 miles out, and then back in. They become part of you, and very comfortable...When I say efficiency of your motion is off the chart...that means you go from place to place, at almost no effort....that moving in water becomes more like moving in air...if that analogy helps

---------- Post added September 28th, 2015 at 10:42 AM ----------

Ron Smith will be back in Boynton Beach to dive with me just before or after the DEMA show....I'll be shooting some video of his new bi-fin designs.
If any of you guys would like to chat with a brilliant fin designer, or try some of his fins, let me know--you could dive with us when we go out.

And no, I am not trying to sell Ron's fins....they are far to pricey to sell on SB....the real takeaway is kick shape, muscles used, and leverage....and when you see this, it helps all other fin discussions.....It actually also helped me to get way more efficient with my DiveR freedive fins, which led to me getting a kick shape perfected with them, that I could use to easily keep up with Gavin and Suex scooters, on hour long dives. It led to more of an oscillating--- less amplitude----higher frequency kick, than most freedivers use...and it is using dolphin kick for this, with some of the coordination I learned from using the Dol-Fin

 

[gkrane]

plus it was designed to provide maximum acceleration while using less energy for sustained kicking. They also frog kick well.

Just so you don't think I think Force Fins are the only fins to use - my wife normally dives with a pair of TUSA Splits - we just know that they have to be replaced every 2 year - because she hates booties and prefers a full foot fin. She has a pair of Excellerating FFs that she uses only for shore diving in Bonaire and when we do the wrecks in Key Largo (she found out that the splits don't cut it when the current kicks up). I have no problem with her choice.

Just to put things in perspective. Bob Evans signs and numbers every pair of fins made with the Tan Delta Material. He has produced these fins for about 15 years (none in the past 2-3). As of right now, Bob is hoping to begin producing Tan Delta fins in the next year, since he now has a new facility where he can directly oversee the production and continue to produce experimental fins.
I did a little checking with some of the other divers that use Tan Delta FFs and have figured out about how many have been produced.

Excellerating FFs - 225 - $700-$800
Extra FFs - 150 - $600-$700
Flying FFs - 120 - $600
Originals - 100 - $500
Hockey - 75 - $400

Total Tan Delta Fins - 670 - or about 45 per year. This is not a major source of income or profit for Force Fins - these are strictly produced for those that find that the added performance (defined as each individual sees fit) worth the cost.

So, it is no loss to Force Fin if you don't feel they are worth the price - no one is "selling" these for the company. Those of us that are proponents of the fins are trying to do nothing more than share our experience and offer up what we see as a better fin.

All this garbage about signed fins is irrelevant. Sounds like some guy playing in his garage with prototypes and selling them to anyone who buys the hype. "Tan Delta" material. This is amusing since it isn't a material it is a term for the Tangent of Delta.

---------- Post added September 28th, 2015 at 10:16 AM ----------

In addition to the whiskers I just noticed you can also purchase speed pods and sharks teeth for your force fins for another $100 each. I hope you didn't pass on those options.

Force Fin Wings can be added on to a fin blade, allowing you to take controll and optimize the way you want the water to work for you.

• Speed Pods are shapped like half raindrops. Water speeds up as it flows over the curved hydrofoil shape, reducing drag and turbulance to increase efficiency.
• Sharks Teeth are used to cut through the water and channel it through the opposite direction of travel before it meets the fin blade.

Does NASA know about this guy? Bob also need to replace his web editor since he has typos on the site.

 

[jadairiii]

...way more efficient with my DiveR freedive fins, which led to me getting a kick shape perfected with them, that I could use to easily keep up with Gavin and Suex scooters, on hour long dives.....

Hate to burst your bubble here Dan but there aint no way you would keep up with my xJoy37 (easily or otherwise) if I was on the trigger for a solid hour, even at half power. And an XK, well lets not even go there. As for a Gavin, possibly, since I have never seen a Gavin last a full hour without the batteries dying or flooding...

I have done dives when my buddies and I have been on the trigger over a hour, solid (from 185' to 20').

 

[TN Traveler]

The fact that the Tan Delta material fins are signed and numbered is a way to figure out how many have been produced - that is all.
Because of the nature of the Tan Delta polyurethane - it is not feasible to make it in large batches nor hold it for extended time to produce more than a couple of fins at a time. Yes, these fins are individually produced in small quantities, by hand. Expensive materials, skilled labor and they will never be mass produced = higher priced. Only for those who are willing to pay for that something extra.

As far as your comment about profit - Fiat makes a profit on Ferrari and Force Fins makes a profit on Tan Delta fins - but in neither case is the profit a major part of the company's profits. You can purchase a Corvette with performance almost as good as a Ferrari for a lot less $$$ - but some would rather have and pay for that extra​ that the Ferrari provides. To each his own.

 

[gkrane]

The fact that the Tan Delta material fins are signed and numbered is a way to figure out how many have been produced - that is all.
Because of the nature of the Tan Delta polyurethane - it is not feasible to make it in large batches nor hold it for extended time to produce more than a couple of fins at a time. Yes, these fins are individually produced in small quantities, by hand. Expensive materials, skilled labor and they will never be mass produced = higher priced. Only for those who are willing to pay for that something extra.

As far as your comment about profit - Fiat makes a profit on Ferrari and Force Fins makes a profit on Tan Delta fins - but in neither case is the profit a major part of the company's profits. You can purchase a Corvette with performance almost as good as a Ferrari for a lot less $$$ - but some would rather have and pay for that extra​ that the Ferrari provides. To each his own.

Read post #85

 

[danvolker]

Hate to burst your bubble here Dan but there aint no way you would keep up with my xJoy37 (easily or otherwise) if I was on the trigger for a solid hour, even at half power. And an XK, well lets not even go there. As for a Gavin, possibly, since I have never seen a Gavin last a full hour without the batteries dying or flooding...

I have done dives when my buddies and I have been on the trigger over a hour, solid (from 185' to 20').

Jadairiii,
I have not scootered with anyone with your scooter...just Gavins and the Suex Matt Cain has.
I am well aware there are scooters and Submarines exponentially faster than me
In discussing speed of swimming, it is so ridiculously subjective--I needed some kind of baseline to establish about what kind of speeds I am talking about, for what performance fins are capable of.

That being said, I'd love to have you dive with us some time, and check out the xJoy37 !
We have a big area Bill Mee, Matt Cain, Ben Hefflinger and I are cruising each Saturday afternoon now....were calling it the Badlands of Boynton....It's an area that runs for miles between 115 and 150 feet deep, with a series of ledges.....We have found one ledge line at around 130 with some amazing lobster concentrations.....and we know this is an area with some huge undercut ledges--ledges we hope to find some fresh water conduits in--based on the geologic stratas of this area...
This is a scooter dive ..obviously ...I dont try to swim at scooter speeds at these depths....

 

[TN Traveler]

Read post #85

You mean after you edited it??

All the add-ons are based on known science - various style vortex breakers to reduce drag and direct fluid flow. Ever looked out on the wings of an airplane? They have similar devices added on.
And yes, I have whiskers on my Excellerating FFs - if I was looking for maximum speed, I would install speed pods to reduce drag.

I know it seems foreign to some folks that there is some science that can/does improve fin performance. But we do live in a nation of the scientific/math challenged/deniers.