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June 2019

Buyer’s Guide to Scuba Fins

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BUYER’s GUIDE TO SCUBA FINS – WHY FINS MATTER AND HOW TO PICK THE RIGHT PAIR

(aka, an old dog learns something new)
By:  Vandit Kalia (Vinnie)

How to Buy Scuba Fins

Go to any scuba forum and ask what the most important bit of diving kit people should own, and the answer is going to be “mask”,  “dive computer” or “regulator”.       Makes sense.   Masks are probably the most likely point of discomfort on dives due to improper fit.   A dive computer is the single most important bit of kit that a diver should have, in order to take ownership of their safety (as anyone who has taken a course with me will have heard me reiterate over and over again).    And regulators – well, that is obvious as well.
Now, a little side trip.   I am a gadget freak, but I am also a creature of habit.   Once I find something that works with me, I stick with it.    I have been using Apeks regulators since the late 90s:  they’ve gone ice diving with me, they’ve been inside the Andrea Dorea with me, they’ve endured far more abuse than they should have and they have kept ticking.    Similarly, for fins, I have been using Cressi Masterfrogs since 2000 or 2001.   They are large, they are stiff, they don’t have any fancy technology, but they provide thrust and precision control like no other fins I have used (and have much better buoyancy characteristics in warm water than the only other fin that comes close, the Scubapro Jetfins).     So that’s what I dive with.   But Cressi, in their wisdom, discontinued the Masterfrogs and replaced them with a lineup of fairly mediocre, “me-too” fins which do not stand out in any way.
So that got me looking for a replacement when my current pair, which is 10 years old, finally wears out and I have been trying out various fins from Mares, Scubapro, Apeks and Technisub to find “The Next One” (@TM Vikas Nairi).
Vinnie’s Mythical Cressi Master Frogs

Vinnie’s Mythical Cressi Master Frogs

 And in my quest, I have realized something:  fins are probably THE most significantly under-rated piece of dive kit.   In theory, we all know the characteristics of fins:   they come in varying level of stiffness, buoyancy and thrust.   Some require faster kicks (equivalent to high turnover/cadence in running or cycling), some require slower, more powerful strokes (my Masterfrogs).    Some are easier to kick but top out at moderate thrust – others provide greater thrust but require more power.   Some are softer and easier on the legs.   Yet others use fancy technology (split fins, gears, channels, springs, etc).    And yet others are designed for flutter kick while some are better for frog kick.
But if think about it – if you rent gear, when was the last time you ever paid attention to which fins you were provided?    I mean, it certainly isn’t something I have prioritized as a “must own” item to other divers looking to buy their gear, focusing instead of mask/computer/regulator as well.    But recently, I have had a change in my thinking.
This realization was kindled over the course of two separate Diveindia Outbound trips – one to Malapascua and one to Maldives.   In both cases, I was using new fins.   In Malapascua, I was simply unable to get into horizontal trim, despite the rest of my kit being my usual gear.     My legs would keep sinking and since i was diving without any weights, I had no real option to adjust my trim.       That made photography a singularly uncomfortable experience, my air consumption was about 20-25% higher than normal and throughout the dive, I felt as though I was a newly-minted Open Water diver again.   In Maldives, the trim was better but in a current, I outkicked my fins, and possibly for the first time in 2 decades, I was struggling to move in a current (the Cressis havent seen a current they cannot wallop – if a diver has the leg strength to swim against the current, the Cressis will make it happen):  I was working far harder and moving far too slowly than I could/should have.
Mares Quattros

Mares Quattros

 I’ve dived in BCDs that are too large or too small for me (including an XS – and those of you who have me know that at 6′ and 82kg, I am definitely NOT an XS).   I’ve worn masks that pinch my nose, used regs with super-high breathing resistance and dived while overweighted by 3-4 kg (although not all at the same time).   Did I enjoy any of these experiences?  Not particularly, but it wasn’t a particularly big deal.    So while I do prefer the comfort of my own gear, I can make do with pretty much anything that is reasonably close.     Except with these fins – with these fins, it wasnt just a mental thing.   I was physically affected during my diving.
So that got me thinking – if my choice of fins messed up my diving zen so badly, what are the implications for all the people who have recently learned to dive, who are going on diving trips and are wearing fins that may not be optimal for them?       To what degree is a diver’s trim (and therefore buoyancy), breathing rate and general comfort level in the water, especially in currents, affected by poorly-matching fins?
So we modified our buoyancy specialty in certain cases to make sure we spent time experimenting with various types of fins – and we tried this with divers of varying levels (beginner to over a hundred dives).    And it has proven to be a game-changer for a significant majority of the divers – in most cases, there was ONE Goldilocks fins which just made the entire system (BCD, weight distribution, kicking, buoyancy) work together in a significantly better way.
And really, it makes sense.      Fins may not be very heavy, but they are the furthest item from your center of buoyancy/gravity and so exert the greatest moment on your trim.    A small change in the buoyancy characteristic of your fin can have a greater impact than a kilo extra on your belt.     Then add to that your kicking style – do you prefer slower, more powerful strokes or shorter, faster kicks, and which affects your breathing pattern more?      The right fins address all these issues.
Scubapro Seawing Novas

Scubapro Seawing Novas

 So what is the takeaway for you as a diver?   If you have ever had buoyancy and trim issues, or struggled in a current, look into not just weighting and distribution, but also fins as a source of fixing these problems.     Even if you have not had any issues with currents, it may still be worth trying to find the Right Fin – it may not be as critical but going from an Ok Pair to The Right Pair is very similar from going from being almost properly weighted to properly weighted – it feels significantly better.
To help you with the process of evaluating fins, I have created a framework of 5 attributes for evaluating fins.

HOW TO EVALUATE FINS

The following 5 attributes of a fin provide insights into its performance and should help you narrow down on fins that work best for you:

1) Thrust:   This is a measure of how much propulsion a fin provides with a single kick, and depends on the length of the fin, its stiffness as well as the overall design.

2)  Beat Rate:   This is a measure of how frequently you have to kick in order to get the optimal propulsion.     A direct analogy would be running, where your speed depends on your stride length and turnover or how many steps per minute you take.   Beat rate is the equivalent of steps per minute here, with thrust being the equivalent of stride length.
3)  Stiffness:    This is a measure of how much force you have to (or can) exert per kick for optimal propulsion.   In general, greater stiffness typically results in greater thrust, but manufacturers are always trying to find clever designs to improve the thrust:stiffness ratio.
4)   Buoyancy:   This tells you whether the fin floats or sinks in the water – which can affect your trim.   These days, most fins tend to be more or less neutrally buoyant, although a few notable exceptions do exist.
5)   Bite:   This is a term i have coined to describe how well you “feel” the water when you kick – your proprioception, in other words.     To use an analogy – when you do the front crawl, you learn to develop a feel for “holding the water” in your hand when doing the pull part of the stroke.    Similarly, you have a better feel of the water with some fins than with others.   That is bite.    Why does this matter?   This is essential when you are trying to make small precise movements in limited space – eg, inside a shipwreck or while engaging in underwater photography.
So what does all this mean?
Thrust and beat rate together give you a measure of the propulsion provided by a pair of fins.      You can get the same propulsion by using a high-thrust fins kicked at a low rate (the equivalent of mashing a big gear on a bicycle) or by using low-thrust fins kicked at a high rate (high cadence spinning).      The former is easier on your lungs but harder on your legs – the latter will increase your HR to some degree, but is easier on your legs.
Stiffness tells you how much effort is required to get that propulsion.    Actually, to some degree, stiffness and beat rate are linked – stiff fins tend to lend themselves to lower beat rates, whereas softer fins tend to lend themselves to higher beat rates.   But I feel it is worthwhile enough to keep stiffness as a separate category because it doesn’t just affect propulsion but also leg comfort.   Also, it is possible to “outkick” your fin if you exert a larger effort than the fin’s stiffness allows it to handle – in such cases, it is better to increase the beat rate rather than effort per kick.
The last 2 characteristics aren’t about propulsion but about control and balance in the water.   Buoyancy of fins tells you how it will impact your trim in the water, as explained earlier in this article.      There is no right or wrong attribute here – a lot depends on your trim characteristics (defined by your body and your gear).
And lastly, bite gives you an indication of how much precise control you have in the water with the fins.     I created this term while trying to understand why I liked some fins more than others even though both of them were equally effective in the water.    The words that came into my mind were “mushy” vs “precise” – and it is a significant factor in determining how good a pair of fins feels while diving.

OTHER FEATURES OF FINS

 In addition to the attributes mentioned, there are other aspects of fins that also go into a purchase decision.
The first of these is whether you want a Full Foot fin or an Open Heel fin – the former are meant to be worn on bare feet, whereas the latter require the diver to wear booties (or at the very least, neoprene socks).      The benefit of full foot fins is that they can be very comfortable and feel very secure – and also require one less piece of equipment.    On the flip side, fit is very important – if the foot pocket doesn’t match your foot shape and is too loose or tight, it can hurt or result in blisters.     Open heel fins are more flexible in terms of fit, and also allow you the ability to wear the fins over a broader range of water temperatures.   Plus, if you are doing shore dives, dive booties are very nice to have – especially on rocky water entries.
Another point to consider is fin size and weight – in this day and age of ever-miserly baggage allowances, large fins can be harder to travel with.     I am always on the quest for smaller and more compact fins – but so far, I have yet to find one where the smaller size comes with no compromises (there are a couple of fins where the compromise can be acceptable in some conditions – but not universally so).      And given the cost of a diving trip, the slight increase in inconvenience of taking the Right Fins is significantly outweighed by increased comfort when diving.   Your mileage may vary, of course.
The last item is what I call “high tech features”:  fancy designs meant to shift the thrust-to-effort ratio.  These include gears to adjust stiffness, split fins, funky designs, etc.    I have tried a bunch of them, and honestly, been underwhelmed – however, I also admit that while I like playing with new tech, it also takes convincing to get me to give up what has worked well in favor of the latest-and-greatest:  especially when this latest-and-greatest often comes at a much higher cost.   As with most things, personal preferences come into play.    Personally, instead of just looking at the technology, I would evaluate fins like this using the 5 attributes I had mentioned earlier – ultimately, that is what matters, and not how “funky” the fins are.   Obviously, if all else is equal, you can always choose to get the fins that are more high-tech:  nothing wrong with wanting cool tech.

 

SELECTING THE RIGHT SET OF FINS FOR YOU

 So now that you have read all of this, how do you actually select the correct fins for you?
Unfortunately, there is no clear answer to this.   Because we all vary in our dive skills, personal fitness, swimming skills, buoyancy characteristics and kicking style, what works for me will not necessarily work for you – and by the same token. a set of fins that I discount may very well be the best fins ever for you.
The only way to find the right set of fins is to try out as many pairs as possible.   The next time you go diving, try out a few different fins, if you can.   Note the model and try to evaluate how they feel in terms of thrust, beat rate, stiffness, buoyancy and bite.     Make a note of what you like about it and what you don’t (sometimes, you may have to try more than one set of fins before you start noticing these differences).      You will note that some fins feel a lot better and improve your comfort in the water drastically – if possible, try to identify what particular aspect of those fins is contributing to this.
To help people with this process, we have also put together a basket of Recommended Fins – these are available to try out in our dive centers in the Andamans, as well as at our @Home dive centers in Delhi, Bombay, Bangalore and Chennai.      We have selected fins that, from experience, have worked well for most divers – each of these fins are slightly different from the other in terms of attributes, and we feel confident that most divers will be able to find something that works for them from this set.
Contact us to set up an appointment to try this out!

Author:   Vandit Kalia (Vinnie)

Vinnie is the founder of DIVEIndia Scuba & Resorts, and has been diving since 1991 and teaching since 2oo1.   A NAUI Course Director, SSI Instructor Trainer and TDI trimix diver, he is also a keen gadget head and always interested in digging deeper into the nuances of dive equipment and trying to figure out what works, what doesn’t and more importantly, why.