Extreme Dolfinism G2

[Fondueset]

Here is the Pilot Review in full - probably should've posted it here to begin with..

"The Dol-fin Pilot is a high-performance, very practical recreational monofin. Easy to travel with, durable, and with overall performance somewhere between a Nemo class monofin and a competitive Hyperfin."

I’ve been running around with Ron Smith’s Dol-fin Pilot for awhile now. Pool sessions, open water, etc. etc. I’ve formed an impression of this device as a recreational monofin.

The problem is I am accustomed to hyperfins. Most all my diving is with my Starfins hyperfin and, while the Dol-fin Orca can be reasonably compared to such a fin, the Pilot is a recreational fin and best A/B’d against the industry standard Waterway Nemo.
My perspective is insatiably biased.
It was not until I saw my dive buddy Jason (a long-time Nemo aficionado) swim with the pilot a few times, and got his feedback, that I felt ready to write this review.

(The Nemo, by the way, is an excellent recreational fin. The overall quality, and quality of the blade itself, is pretty much impossible to beat for the price. Jason uses one of my old Nemos – which is on it’s third owner and is more than 10 years old. The Nemos are comfortable, durable and have excellent performance. )

Lets start with the basics:

Durability:

Not even a question. The Pilot will outlive any other recreational fin.

Travel:

No contest. It breaks down way smaller than any other monofin.

Comfort & Fit:

The cycling shoe interface means excellent comfort – even in very cold water.

Ease of Use:

Well yes – it’s easy to use; but it does not reward bad technique as well as a Nemo. However, it rewards good technique better.

Design:

The Dol-fin Pilot is a study in form-follows-function elegance and minimalism.

Support:

Absolutely top notch.

For this review I’ve focused on both of our observations during Jason’s dives with the fin. He’s been using a Nemo exclusively for a number of years and is very picky and impatient with substandard equipment. Dive Time is Sacred – we will not-for-long be burdened with gear we don’t like.

I gave Jason the fin in October – water temps are now down around 10C and less – viz is awesome and some of the fish are stultifyingly difficult to get next to. In addition to the cold water, we have to swim a long ways to get to some of our favorite sites. It’s the best time of year to dive around here.

We both pull substantial floats – mine is a Banks Board, Jason’s; an OMER Shardana ( a most rocking float, btw – no longer in production). We both have big flags on long masts that catch the wind like sails, so it was good to test the fin on a couple of very windy days.

Our dive site was about 1/3 mile out – with the wind behind us on the trip out (8-12 knots).

"The Famous Liquivision Xen"

At these temps (air maybe 8 C, water; 10 - aka 49.2f, according to the famous Liquivision Xen) and with that wind, it’s a balance of enough exertion to stay warm and saving something up for the longish dives required to make Lake Trout comfortable with us. (They mosey on over at a very leisurely pace after you’ve been down at least 1:45 – which means 2:30 to 3 min if you want a reliably close encounter - except for this one, which was napping on the bottom).

Perhaps the most striking thing I noticed was during the trip back in:
Jason was moving along very well on the surface – wind against him and trailing a float that he could pretty much ride with the wind on the way out.

Interesting.

I kept a lid on it – I wanted his unvarnished observations after a couple more sessions.

So:

We found the pilot superior to the Nemo for surface swims – less energy – plenty of speed – more distance. I expected really good dynamic performance, but this was a surprise.

Most of our dives during these sessions were only just past 10 meters. (earlier in the year I did a number past 20) At these depths and wearing 5 mil suits we found the Pilot inferior to the Nemo on the trip down.

I think this is because it weighs less; hence does not drive you down as well on a duck dive, and because 10m is really not enough distance for the foil’s efficiency and reduced drag to make a difference. At greater depths I suspect the efficiency curve would change in the Pilot’s favor.

The trip up was no problem, but is difficult to judge since the buoyancy of our cold-water suits kicks in pretty quickly in such shallow water. My deeper tests with the Pilot showed it nominally inferior to my hyperfin. It feels lame coming off the bottom – but once you relax into the flow with it, it moves along quite well (Same past the first 10 or 15 feet on the way down.)

Jason whined a little about maneuvering with the fin – this is just because he is accustomed to the feedback of that big blade. Sensing right alignment with these foil-based fins takes a little time: “Demonstrate some adaptability” said I.

Conclusions about performance:

Our consensus is that the Pilot exceeds the Nemo in horizontal swims – surface or submerged.

We’re not so sure about depth, but hypothesize it will match or exceed.

Things not liked:

It’s negative at the surface, not super-negative; but more so than the Nemo – even with a 5 mil suit. We’d like some kind of float to make it slightly positive.

I don’t particularly like cycling shoes. I don’t like the way they lock my feet in and I don’t like the rigid arches. I think Ron should make an adapter for bifin foot pockets such as Omer and C4. Most people will probably like the shoes just fine though, and they do have several advantages (force transmission; tight or loose fit for different socks; sizing).

The straight foil can get tangled with your floatline. This is pretty picky really, since it is easily avoided by paying attention, but reviews that don’t say anything bad sound cheesy to me.

The Big Picture: The Dol-fin Pilot is a high-performance, very practical recreational monofin. Easy to travel with, durable, and with overall performance somewhere between a Nemo class monofin and a competitive Hyperfin.

Odds are it’ll fit in your luggage.

I think the thing is a masterpiece.

For what it’s worth, while the Waterway Nemo will always have a warm place in my heart, since I’ve got used to hyperfins, it feels hopelessly awkward to me. Not so the Pilot.

In fact, in terms of feel, I like the pilot better than the better-performing Dol-fin Orca. It has less mass and swims more easily on the surface.

Things You Should Know: As I’ve said of the Orca – if you have experience with bifins and monofins you will need to rework your feedback thing.

You do not feel the power in the same way with these foil-based fins

Instead; Relax and watch the bottom going by. Explore how well you move with very little effort and motion.

You can work as hard as you want to – but these fins are all about minimizing effort. They feel almost like cheating compared with conventional fins.

Dol-fin Pilot: HIGHLY RECOMMENDED

Disclaimer: I have no financial relationship with Ron Smith. He doesn’t give me free stuff or money.

 

[REVAN]

I like the extra pictures.

 

[Fondueset]

I like the extra pictures.

Added one of the pilot in situ.

 

[cdavis]

derelictp: You probably know about this already, but its worth thinking about ahead of time. The difference is going to surprise you.

Dol-fins very little drag relative to bifins or any traditional monofin. Low drag makes them fall differently in the glide portion of CW. Its much more important to get your buoyancy/weighting distributed on your body correctly. Otherwise the fin will want to fall faster than the rest of you. A neck weight is critical. Put as much weight on the neck and the least on your belt that you can manage. Your Orca has a float inside it, so that's already done. You might find that different thickness of wetsuit will make a difference on how you distribute weight. Expect to need some experimenting to find the right combination.

Have fun!

Connor

 

[Kars]

I will have to wait until februar before I am able to take the Orca for other than pool-doving. I will do dives deep enough (with a glide phase) to get an opinion about it for CWT and offcourse some reporting here. Everything I have felt so far indicates that it will be as good or better for CWT as it is for DYN.

I'm not entirely sure, in particular I'm thinking about the start after the turn, and the negative phase ascension, especially when / if the diver is very negatively buoyant, wearing lots of weight and a thick suit. Maybe the overpowered foil will slide sideways, maybe it's harder to gain momentum, and to keep it, maybe it demands more concentration; which may be hard to do under N2 narcosis? E Fattah choose a Hyper fin for his excellent North American CWT record, even though he had an Orca at his disposal, I believe, there must have been some reasons.

Hyperfins often have a bit of an V bent, which helps a lot to centre the blade.
Ron have you got any idea how to make the foil self centring a bit?

 

[REVAN]

Eric Fattah had his Orca delivered about 5 or 6 days before flying to Dean's Blue Hole for Vertical Blue. He used his hyperfin in the competition to set his record because that is what he had trained with for the year prior to the competition. As the saying goes, "train like you compete, and compete like you train". That is exactly what he did. He has since told me that he has no doubts the Orca is superior in performance to his old hyperfin.

The side slipping thing is a coordination and muscle memory issue. The foil is different from a flexing fin and the coordination isn't the same. In the beginning, many people get their feedback reversed and just don't use the right corrections to fly it straight. Once the new process of coordination is learned, the side slipping disappears. I never have issues with side slipping.

 

[derelictp]

.

derelictp: You probably know about this already, but its worth thinking about ahead of time. The difference is going to surprise you.

Dol-fins very little drag relative to bifins or any traditional monofin. Low drag makes them fall differently in the glide portion of CW. Its much more important to get your buoyancy/weighting distributed on your body correctly. Otherwise the fin will want to fall faster than the rest of you. A neck weight is critical. Put as much weight on the neck and the least on your belt that you can manage. Your Orca has a float inside it, so that's already done. You might find that different thickness of wetsuit will make a difference on how you distribute weight. Expect to need some experimenting to find the right combination.

Have fun!

Connor

Thanks Connor !
My config in tropic conditions is normally:
1,5kg neckweight
1,5mm or 2mm Eliossub full suit

I may have to add 0,5 kg to the neckweight to counter the Orcas bouyancy and increase the top-heavy-ness

 

[Philip Fennell]

The side slipping thing is a coordination and muscle memory issue. The foil is different from a flexing fin and the coordination isn't the same. In the beginning, many people get their feedback reversed and just don't use the right corrections to fly it straight. Once the new process of coordination is learned, the side slipping disappears. I never have issues with side slipping.

I can confirm Ron's assertion about, 'once the new process of coordination is learned, the sides lipping disappears', and that I've reached the point where I'm training with the fin without thinking about it. That's a good place to be. My next challenge is to hone my stroke to get the best out of the fin.

 

[derelictp]

I'm not entirely sure, in particular I'm thinking about the start after the turn, and the negative phase ascension, especially when / if the diver is very negatively buoyant, wearing lots of weight and a thick suit. Maybe the overpowered foil will slide sideways, maybe it's harder to gain momentum, and to keep it, maybe it demands more concentration; which may be hard to do under N2 narcosis? E Fattah choose a Hyper fin for his excellent North American CWT record, even though he had an Orca at his disposal, I believe, there must have been some reasons.

Hyperfins often have a bit of an V bent, which helps a lot to centre the blade.
Ron have you got any idea how to make the foil self centring a bit?

My acceleration with the Orca is getting much better and at the last session I did not experience sideslipping despite powering the fin quite a lot.
I have to mention that I also now have the hydrofoil in the extended (longer) position which for me increased the performance but mainly to an even higher "gear".

I also added a little simple part to the frame that makes a progressive "coil spring" function to the suspension that only sets in when the hydrofoil rotates very much from harder acceleration or higher stroking speed. The low speed cruising is not affected at all. It felt very good on my last session but to early to say if that was the reason it felt so good under power. The progressive spring function may both stabilize and make the thrust better under high power stroking.

I also on the last session went back to my traditional fin again to check and it felt totally inferior to my Orca when I got even more used to it. With that said for me it's a nobrainer to decide which fin is going to with me to the Blue waters in the Indian ocean.

My feeling after getting used to the hydrofoil is that this is the high end technology of fins with both the highest energy efficiency and still room for further tuning. (Having spent both much time an money on developing solutions built on traditional blade I am not "biased" at the hydrofoils favour either.)

I may be wrong but time will tell ;-)

 

[cdavis]

I'm wearing an x18 with a lot of added buoyancy, a 1.8kg neck weight and, at most, a 1 mil suit with nothing on my legs. Your weighting sounds close, but the exact will take some experimenting. One measure that you can try without depth: You should be able to float flat on the surface in fresh water, completely relaxed, and not have your legs sink.

Something else, I think you will find that, with proper weighting and good streamlining, you will sink a little bit faster than with a traditional mono. When you get there, I'd like to know if that is true.

Tell us a bit more about that spring, pics?

 

[derelictp]

I'm wearing an x18 with a lot of added buoyancy, a 1.8kg neck weight and, at most, a 1 mil suit with nothing on my legs. Your weighting sounds close, but the exact will take some experimenting. One measure that you can try without depth: You should be able to float flat on the surface in fresh water, completely relaxed, and not have your legs sink.

Something else, I think you will find that, with proper weighting and good streamlining, you will sink a little bit faster than with a traditional mono. When you get there, I'd like to know if that is true.

Tell us a bit more about that spring, pics?

Thanks for input about weighting, seems that my normal config is a good start.

About the spring-function, it's really nothing special. It's a rubber part made of sheets of 5mm para-rubber in hardness 40 shore. I have made it so that it suits inside the frame in front of the hydrofoil and when the hydrofoil rotates more than approx 45 degrees, it reaches the rubber and is progressively restricted by an increasing very flexible resistance from the rubber and seems to steer the hydrofoil to be more stable at the end of the rotation. See pic. I may take some more pictures from different views etc. if this little "mod" is succesful.

 

[Fondueset]

In my dynamic tests with the Orca I found that blade size, beyond a certain point, didn't make much difference - and was even an impediment . When I was testing the Orca and X-22 in open water doing vertical dives it was a different story.

Size matters in the vertical. Particularly in the trip up. But your suit and weighting make a huge difference as well. In my 5 mil suit - with a 3 mil undervest and about 11 lbs of weights (about 7 on my neck) the difference becomes very noticeable. In a lighter suit, with fewer weights - not so much.

 

[REVAN]

I want to thank those who take the time to write about the DOL-Fin products. It really does help to know that there are people out there that care enough to take the time to do this and write about their experiences of their own accord. So, thank you. What you have to say matters, and not just to other potential customers who are looking for more information on a new and not well understood technology. It makes it easier for me, as the developer, to continue working on the project with enthusiasm and will likely result in the development of better products in the future.

 

[derelictp]

In my dynamic tests with the Orca I found that blade size, beyond a certain point, didn't make much difference - and was even an impediment . When I was testing the Orca and X-22 in open water doing vertical dives it was a different story.

Size matters in the vertical. Particularly in the trip up. But your suit and weighting make a huge difference as well. In my 5 mil suit - with a 3 mil undervest and about 11 lbs of weights (about 7 on my neck) the difference becomes very noticeable. In a lighter suit, with fewer weights - not so much.

Fondueset; What blade size did you prefer for vertical diving and what sizes have you tried ?

 

[REVAN]

Fondueset has had access to 25, 30 and 32 inch foils.

New video from my recent trip to Florida for the DEMA Show and some diving in strong currents and rough water:

 

[derelictp]

Fondueset has had access to 25, 30 and 32 inch foils.

New video from my recent trip to Florida for the DEMA Show and some diving in strong currents and rough water:

Interesting prototype, it's offcourse hard to see but it looked effective and the angle of attack in the, what looked like a segmented blade seemed nice.

 

[Azrael3000]

That's a really intersting bi-fin design. From an engineering perspective, what was your motivation / inspiration for that?

 

[REVAN]

That's a really intersting bi-fin design. From an engineering perspective, what was your motivation / inspiration for that?

A couple years ago I was going to the Freedive Paradise competition in Hawaii to help with safety diving. However, I only had monofins. I figured I should have a pair of bi-fins for the role I'd have at the competition, so I made some.

I wanted to get rid of the rubber on the fin blade. I thought it strange that manufacturers would make expensive carbon or glass fin blades for efficient energy return, but then wrap this high performance material in rubber side rails which deadens the blades response. I also wanted to make the fin tough and modular so that it can break down for easy traveling similar to what I have become accustomed to with the DOL-Fin monofins. Remove 2 screws and a fin will break down to fit in a standard large suitcase without bending the fin blade. Remove 4 more screws to remove the fin blade from the shoe fixture and it will fit into a carry-on bag.

Since I started this project, I've probably made about 20 different test configurations to get to the point where I'm really happy with the fin's performance. The flexing fin is very different from the hydrofoil fin, so there was a lot to learn about the parametric variations that impact the fin's performance. I approached the engineering similar to how I approached the DOL-Fin, and in the end, I think it is a good performing bi-fin and I have learned a lot about why it is working the way that it does.

I'm thinking of taking the design to production and I'm wondering what others think of the concept. I'm planning to launch a thread in the bi-fins section, but I'm interested in what my monofin followers have to say about it.

I also need a product name to go forward with. In development, I've been calling it "Stereo Reticulatus", referring to the non-symmetric left-right fins and the network of reticulated interlocking hydro-panels that make up the fin blade. I'm not sure that name is good for the product and sales, but I've been stalled coming up with anything better, or just abbreviating it down to something like "SR-1". I liked the name "Raptor", but it's being used on for a Mares split-fin product. I've also considered "Celeritas", Latin for swift or rapid, but my wife says it sounds related to the sun instead of a diving product.

Please come forth with opinions and ideas....

 

[derelictp]

A bit longer tail - Dol fin Lizard

 

[REVAN]

A bit longer tail - Dol fin Lizard

Interesting... along the same line of thought, maybe "Serpent", "Crocodile" or "Alligator" fin. The hydro-panels do evoke a bit that alligator's armor look.