Monofin Purchase advice

[welljim]

Hi everyone,

I'm trying to figure out which monofin to buy but I'm lost with all the options, I wonder if anyone has some good advice please?

I'm a beginner that doesn't have the chance to dive for more that 2 weeks a year if I get lucky (when I visit my parents back in Greece), but when I get in the water I feel right at home (I grew up by the sea). I've only gone down to 30m deep, which was in a pool when I did my entry AIDA ** last year. During that session I had the chance to try a monofin and I immediately fell in love with the feeling, so now I have to figure out which one would be suitable for my circumstances.

- I live in Whistler which is a mountain resort in BC, so there are no diving stores around - I'll have to order online.
- Even though I don't dive much, I want a piece of gear that will help me enjoy it when I do. That is, I don't want a crappy cheap fin.
- There is a pool nearby so I could train there, but I don't enjoy dynamic all that much. I'd rather have a fin that I can enjoy when CWT, even if I have to compromise when in the pool.
- I have wide feet and big strong legs

Not sure what other information is relevant. Apart from direct product recommendations, are there certain characteristics that I should be looking at? For instance, how do I decide how hard a blade I need, the principle material, etc.

I noticed that there are a few companies out there that just outsource footpockets and stick a blade on, does that result in a noteworthy product? In contrast, some other companies seem to be doing more research, thinking about fluid mechanics, foot anatomy, blade angles, etc.. Does it pay off or is it just marketing? I guess the question can be simplified like that: If you have tried a couple of fins for CWT, have you found one that outperforms the others in your collection and if so how, and which one is it

Is there a good reason why I shouldn't just get the most expensive fin that I can afford? I got the impression from some posts that one needs to have a certain level of experience before a higher-end fin can be enjoyed, how does that work exactly? Would a high-end fin hinter the performance of a less experienced diver like me?

Thanks for your help!

 

[X-Fins]

Dear Welljim,

you can find a lot models in the market as you can see. Mainly two

1) Pro models (angled, with wings, like HYPERS or FLYERS type)

2) Old style models (not angled, no wings)

Old models are not bad at all and still used for long distance finswimmers and also for freedivers, of course. Are cheap, light and being honest enought for too much athletes.

With "old models" you can get better and fast the proper technique, PRO models can be a little hard if you are a dummie.

So, we suggest you to focus in a "old models" to start, will be enough for a long time and when you have defined your needs and abilities go for Pro model.

I hope that help you a little bit.

Best regards

 

[welljim]

With "old models" you can get better and fast the proper technique, PRO models can be a little hard if you are a dummie.

I'd like to understand this aspect if someone could explain, please.

Thanks

 

[JennyWren]

Hi welljim. If you are willing to drive down to Vancouver once in a while you can get lots more diving in, we go out quite a bit!

My recommendations are only based on what I have, so keep that in mind.

I have a Waterway Nemo and a Waterway Glide. I like both these fins a lot. The Nemo is very comfortable and allows me to wear 3mm socks, which is pretty much a requirement in Vancouver waters! I have worn my Glide here but my feet got pretty cold pretty fast.

If you are looking for an entry level fin for training and you want something that you can wear for a couple of hours comfortably, I'd recommend the Nemo.

That being said....I got my Glide this year and I LOVE it. It makes a huge difference, my technique is a lot better, I get a better glide and more power. Definitely easier to go farther in dynamics and deeper in the ocean. However, it does give me some nasty blisters if I wear it for more than about half an hour. I save it for shorter training days and for competition.

Both can be ordered through Performance Freediving's online store. They ship from the Ukraine, takes about 3-5 weeks. If you can order with someone else at the same time you can share shipping costs (I think they will ship up to three on one order).

All the best in your decision, and hopefully we'll see you out in the water 'round these parts!

 

[X-Fins]

I'd like to understand this aspect if someone could explain, please.

Thanks

Yes may be will help some pictures

"OLD MODELS" or "FLAT MODELS"

Pro Models (WInGLED and Angled)

and Hybrid models in between

Let us show you the purpose of the angle

In promodels you will have your foot away from the middle of the blade, so more lever effort and more stress in your toes.

That's the reason we suggest you to get some experiencie with "Old models " as can be friendlier for start to learn and get technique.

If delays in my answers sorry !!! I will be away a litlle bit some days.

Bye guys, enjoy this weekend

 

[REVAN]

The pro models (hyperfin style) are both faster and more efficient than the old models, but there are drawbacks also. In addition to including better streamlining, the hyperfin style monofins also have much higher reaction loads that will require a fairly tight fitting foot pocket to transmit the forces effectively (the higher forces are a byproduct of the streamlining and the longer extension of the fin that results). If your feet are not conditioned to take the fin loads, your experience will not be pleasant. This is the reason why it is always recommended to start with a beginner's fin, as it gives your body time to build up the strength in the bones, tendons and muscles of the feet and ankles that will be required to upgrade to a hyperfin style monofin. Basically, you are breaking up an unmanageable pain curve into two manageable pain curves. :crutch

If you want to bypass the the pain and still go to a pro level monofin, I think the only option would be one of my DOL-Fin Orca monofins. The DOL-Fin Orca is very comfortable and performs at the highest levels available to freedivers (perhaps even better than anything else). The downside is that they are expensive. Of course, I also have less expensive DOL-Fin models as well.

Ron Smith

 

[welljim]

The Nemo is very comfortable and allows me to wear 3mm socks, which is pretty much a requirement in Vancouver waters!

Thanks JennyWren, would you say that the footpocket is comfortable and a good fit even without the 3mm socks? Also, how does the footpocket size compares to your foot size? Would you say that the footpocket fits normal / narrow / wide feet better?

 

[welljim]

Thanks everyone for taking the time to explain, if I'm getting this right, the problem with the pro models is that they are stiffer and less comfortable.

How does the blade stiffness come into play. I.e., does the situation get better if I opt for a hyper-type fin and choose "soft" in the order drop-down box? Would that still be less comfortable than a standard fin?

 

[REVAN]

Thanks everyone for taking the time to explain, if I'm getting this right, the problem with the pro models is that they are stiffer and less comfortable.

How does the blade stiffness come into play. I.e., does the situation get better if I opt for a hyper-type fin and choose "soft" in the order drop-down box? Would that still be less comfortable than a standard fin?

The hyperfin style monofins extend the fin further out from the foot. This does two things. It provides room to blend the large angle foot pocket into the fin blade in a streamline way, which combined with the large angle (30 deg) reduces the fin's drag to improve efficiency. It also acts as an extension arm to increases the amplitude of the fin stroke for a given body deflection. This maintains the necessary amplitude of the fin stroke while allowing the diver's body to remain more streamline which also reduces drag and improves efficiency.

These are good things for performance. However, the cost is that the extension arm increases the torque the fin applies to the feet (torque = force x arm_length). A softer fin blade will reduce the force, but the arm_length is a property of the geometry of the fin. A softer fin blade will also provide less thrust and be more easy to overpower when negatively buoyant at depth (especially when cold water diving in Vancouver).

It is tricky to get a hyperfin style monofin that fits you right. It is common for someone unfamiliar with the equipment to spend $500 to $700 on a new fin only to find out that they need to sell it because it does not fit right. The classic monofins are more forgiving because the foot loads are reduced. Starting with the old style gives you time to get to know other divers and their equipment so that you are not as likely to make a bad purchase when you get to spending the big bucks. Even divers who have been doing this for a long time still run into issues all the time. This forum is full of threads about people looking for advice on how to cut up and re-glue their new monofin to try to get it to fit right.

That said, if you are dead set on getting a hyper style fin, there are people in the industry who will take fairly extensive information from you to try to customize a fin for your foot size and intended uses. I know that Starfins has had a lot of positive reviews from people within this forum. I have not seen or used them personally, but they do look nice in the pictures. There is a lot of information on Starfins within this forum and the fin builder Alex seems to frequent his threads to answer questions and help people out.

Ron

PS - These problems are some of the primary reasons why I got into fin design and construction in the first place. I wanted to make the sport more user friendly. Compared to buying a couple of hypers to get a good fit, a size adjustable and very comfortable DOL-Fin Orca that can easily transition from cold to warm water diving is actually a reasonable way to go.

My story can be seen here:
Gear Review: The DOL-Fin Orca | Feature Article by Eric Fattah on DeeperBlue.com
http://forums.deeperblue.com/monofins/85969-extreme-dolfinism.html

 

[welljim]

Thanks Revan, that was a thorough explanation and made things even clearer for me.

Actually I had a look at your design while going through some of the other threads. I don't have a strong background in fluid mechanics so can't appreciate fully the science behind it, but I'm a glider pilot and have some understanding of airfoil design. Here's what I can't get when I look at the Dol-Fin:

Intuitively, I understand that a traditional monofin (whether 1st or 2nd gen) works by having a large surface that is capable of displacing water while it deflects. Displacing water results in propulsion, due to the action-reaction principal. The larger the fin's surface (all else being equal), the more water it will be able to displace, and therefore the larger the amount of propulsion.

To my understanding, the following is also true: the harder the fin's surface, the more water will be displaced. A consequence of that is that a completely rigid fin would provide the maximum possible propulsion, per fin's sq.ft. However in that case all the displaced volume of water would have to be moved in a linear fashion, requiring a huge amount of energy at the beginning of each stroke, due to inertia. Therefore traditional fins have blades softer than 100% rigid so that they can deflect due to the water's resistance, displacing a smaller volume of it (compared to the potential volume based on their surface), and thus requiring a more manageable amount of energy from the diver. Of course, that results in less propulsion.

If all the above is true, intuitively I would think that the Dol-Fin could not work for the following reasons:

a) The wing (instead of a blade) that it is equipped with, has a substantially smaller surface area compared to traditional fins (whether mono or stereo). Therefore I would imagine that the amount of water displaced cannot be very much at all, making the generated amount of propulsion to suffer.

b) The wing is rigid, and thus unable to deflect at the change of direction of each kick of the stroke. I would imagine that although the wing is relatively small, changing the kick direction when in the "top dead end" and "lower dead end" of a stroke would require a large amount of energy from the diver. If the wing is small enough to not make this requirement pronounced enough to become a problem, then I would image that point (a) above would be exacerbated.

I read the review on the link you posted and the test results seem to suggest that I'm wrong, but unfortunately I can't test the fin to convince myself so I'd like to understand it in theory at least, if possible.

I find the idea of laced footpockets quite promising however, from what people have been explaining here comfort is an issue. While I understand that comfort related to stiffness (also discussed above), people seem to suggest that a good fit to prevent blisters and to allow for cold water use is also an issue. Could you not adapt your adjustable footpockets and sell them separately, to be used with the traditional blades that people are accustomed to?

 

[REVAN]

The traditional monofin is basically a delta wing and delta wings generate the majority of their lift from something called a leading-edge vortex which creates a strong low pressure zone on the first few inches of the fin's chord (the part that is usually covered by the rubber boot). The truth is that this is the part of the fin that is generating your thrust. The rest of the fin (the roughly 18 inches of flexing fiberglass behind the boot) is there to alter the flow field around the leading edge to keep it generating useful lift.

You can think of all that fiberglass as a substitute for the DOL-Fin's suspension system that controls the foils angle-of-attack and keeps it flying efficiently. If the traditional monofins were able to appropriately rotate their foil the fiberglass part of the fin would become unnecessary. Instead, the flexing fiberglass is used to rotate the flow field and the foil remains more-or-less rotation free. This is why the flat monofins still work (and quite well I may add) even though the working part of the fin (those first few inches) is angled such that you would think it would be thrusting backward on the fin's power stroke. Our eyes can't see that the flow field around it has been rotated instead.

When you look at it this way, you will see that the DOL-Fin has a larger working foil than does the traditional monofin, even though the fin itself is physically much smaller (which makes it sooo much more easy to travel with).

 

[welljim]

That's very interesting, I can see how the Dol-Fin design relies on its wing to generate lift, but I always thought that traditional fins relied on the blade's deflection to generate thrust based on an action-reaction principal.

Looking at the Dol-Fin, I'm imagining that I would have to "fly" it in the water by allowing it to "follow" my stroke's trajectory so as maintain a minimum angle of attack (angle that the water flow meets the wing). That is, try to not push vertically any water with it. Then looking at a traditional fin, I'm imagining that to make it work I would need a different stroke: one that would aim to make the blade move vertically in relation to my direction of travel, so as to make it displace as much water as possible.

In other words, am I wrong thinking that a traditional fin's operation is not based on lift, but on generation of thrust by action-reaction? And if that's not the case, how do stereo fins work when they have no leading-edge (i.e., the blade extends on the trailing side of the foot)?

 

[Fondueset]

I would agree the nemo is a good choice. However - another option is to contact Alex at Starfins - I am extremely happy with his fins - as is everyone I know of who has one. For a first fin the Nemo is a great choice - but Alex may be able to go you one better with his basic model - which will likely outperform the Nemo.
My favorite open water fin right now is the Tropol M4 - but it is a hyperfin and they are expensive. It may be best to go with the Nemo - or with a Starfins basic fin initially.
I've reason to believe the Dol-fin is also an excellent investment Natalia Molochanova and Eric Fattah both like it - two very large names in freediving.

 

[welljim]

Thanks Fondueset, I did have a look at the Starfins' website but was put of by the fact that there is no information about each fin, characteristics, etc.. just some pictures. As a beginner, I can't tell much by just looking at a picture.

I also looked at the pdf spec that is available for the Tropol M4, and I noticed that they have 3 variants - the "constant" being for longer distances. But I get the impression that this is a sprint fin, how "constant" is the model "constant"? Do you think that I could use it comfortably for a couple of hours in the ocean. I doubt that I will go diving in Vancouver ever (I should say, "any time soon"), I've looked at some pics and the water looks so mercy. Chances are I'll be using the fin in the med during the summer, so no socks.

 

[Fondueset]

Dude. British Columbia is some of the most AWESOME DIVING IN THE FREAKIN' WORLD!! My opinion of course - but the life in those waters is amazing.

Keep in mind that English is a second language for most of the best fin builders - use the contact option and start a dialogue with Alex. I've found him to be extremely good at building fins and tuning them to your needs.

Another excellent option is to just go for the waterway nemo - not as efficient as what you'll get from Alex - but very comfortable and sturdy- I've owned two - one is on it's second owner - the other on it's third. Get a soft/medium fin. With Tropol - this is the most comfortable fin I've used - not as efficient as my starfins - with it's higher blade angle - but more comfortable. Again, for rec freediving I would go with a distance fin. Contact them and let them know what you are looking for. The Blade on my Tropol is sprint hardness - and extremely well-made. Don't get sucked into the idea of getting a hard blade - my Starfins is soft and is the most efficient fin I own.

Let them know all you're measurements and what you will use the fin for - also if you will be wearing a wetsuit and a lot of weights.

 

[REVAN]

...am I wrong thinking that a traditional fin's operation is not based on lift, but on generation of thrust by action-reaction? And if that's not the case, how do stereo fins work when they have no leading-edge (i.e., the blade extends on the trailing side of the foot)?

Lift based thrust and momentum transfer thrust are the same thing. You cannot have one without the other. More to the point, these two perceptions are just different analytic ways of looking at the same thing.

Your typical bi-fins are really just a degenerate form of the delta-wing used on most monofins. They are what results when the sweep angle of the delta goes to 90 degrees and the leading-edges become 'the sides' of the fin blade. They still generate a leading edge vortex, but it is directed along the sides of the fin blade. The vortex still creates a low pressure zone which generates a lift force, and the water responds to the pressure gradient with acceleration resulting in a momentum transfer of the fluid. We experience the result as thrust.

 

[Fondueset]

Welljim - just to elaborate a bit. Vancouver and environs has given birth to some of the finest freedivers on the planet. PFI started around there - and Eric Fattah, one of the pioneers of modern freediving, is from that area. If I could swing it I'd move there - the diving is fantastic.

I do suggest an entry level fin for you at this time - it will give you the chance to develop some chops and get a feel for what to look for if and when you want a more advanced fin. This would be the nemo - or one of the bifin-style footpocket fins from leaderfins as Xfins has pointed out. OR one of the 'simple fins' style fins from Starfins - (waterway 1 or 2). Also, to repeat myself, - go soft no matter how strong you think you are. If you are dealing with Starfins - just tell him the facts and he will tune the fin for you.

A certain amount of discomfort is part of the learning curve - for me it was several months of excruciating pain - which vanished as my feet became accommodated and I learned to relax them (I started with a Waterway Nemo)

Also - Peter Scott - and excellent monofin instructor - is based in Vancouver and can help you with technique and training tips

 

[welljim]

Well if you had to deal with several months of excruciating pain on the nemo, it sounds like not even that is suitable for me!? I won't be able to dive that often, the possibility of packing a few months worth of dives (in reasonably close proximity) is just not realistic for my circumstances (more on that below, just to elaborate a bit .

I've only used a monofin once before, and that was during the second day of my 2-day AIDA training. That was 3years ago, and also the last time I dove... ehmm, I know.. I wish I was wise enough to ask what that fin was, I remember that I just fell in love with monofins immediately. I can't recall any pain or discomfort for the 15min that I played with it, and it did feel very powerful to my untrained eye. I remember I could launch easily outside the water up to my knees at least, like an aquatic animal - it was a lot of fun. I also tried to get to the bottom of the pool (30m) for the first time, while trying the monofin. I had no problems and going up and down with it just felt so natural. My dives before that AIDA weekend couldn't have been more than 10-15m, unless I was on SCUBA of course.

Anyway, not sure if the above tells anything about how I could acclimatize to the particular fins that we are discussing here. From what you guys are saying, I'm guessing that what I tried was a 1st gen fin? I think I'll shoot an email to Stafins because their contact form does ask for a lot of personalized info, so I'm hoping they'll have the experience to take it into account and build something suitable. I'm also interested in the Dol-Fin, but I wouldn't commit to so much money without the opportunity to try it out. I'm very interested in the theory that Revan has been so kindly and patiently explaining to me, but it still looks too radical for my frame of reference and couldn't truly believe in it without first feeling it for myself. Unless there is a rep in Greece, I don't see this happening

Fondueset, about diving in BC:
I hear what you are saying about Vancouver being a really good diving destination and all.. But the reality for me is that Vancouver is a 2.5h drive (I live in Whistler), which means $60 per diving session on gas and 5h behind the wheel for the round trip. In contrast, the chair lift is a 5min walk from my door and it doesn't cost anything (well, there is a fixed cost on the season pass which I'm buying anyway). I have to work too (unfortunately), so realistically I can't see myself allocating my limited free time on costly trips to Vancouver, instead of going snowboarding on my back yard. The water temperatures here and the visibility don't help either, it's much colder and murkier than what I'm used to. You did do a good job on educating me about the possibilities though, so if I move closer I will definitely consider it!

 

[Fondueset]

That was my experience - in fact in every fin I've used has been painful at first - until my feet acclimated. I wouldn't attribute it to nemo specifically - more likely my feet - and the fact that I was cramming 5 mil socks in there. In fact, once I quit with the socks and found a fin maker that sized them for rec diving it went away. What I do now is cut the toes out of the socks and put them OVER the fin - this works great as long as the air temps arent' so cold that my feet freeze just putting the fin on.

I understand your logistical problems. I'm lucky to live with water pretty much all around me.

 

[Kars]

I pretty much agree with every ones' great points here.

I think going for an "old style" aka - Classic fin - is the best option for someone beginning.
The Nemo is also a very nice option especially for recreational diving because of the bit more comfortable footpockets and the small angle it provides.

Blade stiffness and size is dependent on your body size, weight, strength, use, technique. Alex of Starfins will be able to help you to the best blade and footpocket. For some reason he seems to be able to match people's needs with incredible precision.

Traveling 2,5 hours to a great dive spot seems to me an invitation to spent a weekend at that great dive spot! Hanging out with fellow freedivers is a great experience, and you may get to try and see al sorts of gear.

I went to Spain for my vacation 4 times meeting up with other DB members and having a great time in their blue waters. The experience was well worth the 1350Km drive - one way.

Oh a few words why a classic fin or Nemo is such a great starting fin:
- Affordable,
- Light weight,
- less critical fitting footpocket,
- very good for technique training, because the swimmer is forced to balance the stroke well, have strait legs, feet.
- Since it's affordable you can lend it to interested people in the pool without fear* or heartbreak.
- A great fin to learn the technique and develop your sense for what kind of 'pro' fin you want to have.

*They can unknowingly decapitate some innocent bystanders though.

Btw In monofin training I often use closed heeled scuba fins, kickboard and front snorkel.

Like Fondueset recommends, never start with a hard blade. This is because due to the stiffness your untrained body you will find it hard to find the balance, and apply enough force to the blade so it's used in it's effective (speed)range. Also it will tire you, and your feet quickly. Though most people only need a few weeks (2 - 8 training sessions) to adjust and get flexible and used to monofin foot pockets. Wearing thick socks in footpockets chosen for a naked foot is not advisable. For years I used some hair conditioner and old plastic bags in my footpockets for a nice fit and preventing blisters.

For the classic model fin you can have also different softnesses of footpockeds. Personally for my 73Kg / 1,87m body I like a Model 2 (size) middle distance (blade stiffness) with soft footpocket with glued in neoprene pads and using 3mm neoprene socks.

I need to give Revan kudos for sharing such honest information!

Use the search function on the forum and find and the other monofin threads.

Kars