A Fin Review 2.0: Split Fins VS all others

[g1138]

A few requested it, and now here it is. My take on the controversial split fins. Last time I did a fin review, I was unable to get a hold of a pair. Well this quarter my friend was nice enough to trade my Jet fins with her Atomic Splits (w/ Atomic brand spring straps). So lets begin.
As a bit of background I will be comparing and referring to the fins in my previous review found here:
A Fin Review: SP Jet Fins VS Force Funs VS blade (normal) fins

About Me/Background
I just completed all the requirements to get my Divemaster from UC Santa Cruz. I’m currently a certified AAUS diver with the university. I was certified Basic back in Feb 2010 and currently have 78 dives under my belt both in Monterey, CA and the Northern Mediterranean waters.
I feel in control with my buoyancy and trim.
My technique in flutter kicking is great; as well I’ve gotten to the point where I feel in total control when performing specialty kicks such as frog kicks and back kicks.
I’ve only tried out a single pair of split fins to this date. But I have handled various models of split fins from Scubapro, Atomic, Apollo, and Oceanic. All experience with the Atomic pair was in a pool both as a skin diver and on scuba.
As such this is strictly my opinion, there is no scientific data or numbers to back up what you’re about to read.
Enjoy

Opinions (Click blue names for pictures)
Atomic Split Fins w/ Atomic Brand Spring Straps
Highly specialized fins fully capable and effective in the use of flutter kicks. It is a cruising fin not built to give you any quick burst of speed, but rather a nice even pace with an easy kick. Unfortunately like all highly specialized animals put out of their environment, they lack, and sometimes just plain suck when used for other forms of kicks.
Loved by those who use them, hated by all others (whether they’ve actually used them ever or not)

Comparison - I did not account for silting when testing kicks
The split fin is constructed to have stiff sidewalls with a flexible split fin running down between the two. In my previous review I mis-represented how the split fin works. Unlike other flexible fins, they don’t work on recoil to provide you with thrust. Rather they rely on what manufacturers have termed “Lift”, “similar to an airplane wing”. This is a bit of a misnomer, as you don’t actually get vertical lift, but rather propulsion via water movement.
As you flutter kick, the fin splits in the middle and contorts from the sidewalls to form the shape of a V or an upside down V depending if your leg is moving up or down. This opens a channel in the middle of the fin, which cycles the water in a vortex like way giving you propulsion at the cost of a very effortless kick.
However there is a problem. The Split fin has a very low top speed in comparison to Force fins, Jet fins, and stiff blade fins. Whether you kick in big arching kicks or quick short slow kicks, you will hit the fin’s top speed relatively easily. No matter how hard you kick or how big you make your kicks, once you have gotten to this top speed, there is no going over. In fact trying to go over it with quick bursting kicks actually made my legs just as tired as when I’m kicking with normal flexible blade fins after a 900yd timed swim.

This proves a problem in ocean conditions that are anything but calm. If you are trying to fight through a surf zone or a current that’s faster than the amount of thrust and speed your Split fin can provide, you’re never going to make any headway.
Additionally, due to the nature of the fin splitting and contorting, this makes all fin movements (besides up-down) very hard to do. If you try to slice the fin (side to side) through the water, the fin splits and provides one of the heaviest resistances I’ve ever felt in a fin. This put an large amount of strain on my legs.

For me, I thread water by keeping my legs mostly straight and waving my feet back in forth (pigeon-toe to penguin-toe) and rotate my fins so the following edge is always pointed down with the leading edge pointed up. This for me, is the easier way to thread water with fins, much more effortless than flutter kicking down. Well with split fins this was next to impossible. My legs just kept buckling because each fin wanted to move in a different direction, they wouldn’t slice through the water like a normal fin. The split in the fin acts like a very effective rudder when you’re moving your fin sideways; this is something you don’t want to have happen. You don’t want the fin to control you; YOU want to control the fin.

This inability to slice through the water meant that specialty kicks suffered greatly. Helicopter turns took a lot of effort in comparison to Jet fins. Back kicks required heavy tweaking of the feet to provide the largest fin surface area, yet even still I didn’t move a foot within 10 kicks (something easy done with 3 kicks in Jet fins w/ no foot tweaking). I believe it’s because the fin uses “Lift” to propel and there’s no way you can possible guide this lift to point from your rear to your head. Frog kicks were effective enough. HOWEVER with all 3-specialty kicks, you need to slice the fin through the water at some point as it’s the only way to reset your feet for the next kick. On every reset, I felt a tremendous amount of resistance. If I gave into this resistance my feet would go in haphazard directions, one leg would end up higher than the other leg.

When comparing the Split fin to the Jet fins, most people will say that the Jet fin takes a lot of muscle strength. This is more or less not true. If one were to use a long sweeping kick followed by a gliding period, then you really won’t feel any tiring effects. In addition you can cover large distances quickly using this technique (with any fin). Most beginners kick with short quick repetitive kicks; this is what tires your muscles out. You cannot run a marathon at full sprint, you have to jog it. There is a difference in feeling though. The Jet fins feels heavy when you move it through the water, no matter how you move it. The Split fin feels relatively effortless when moving up and down, however side-side movements feel sluggish, it feels like someone has tied a parachute to your feet.

Unlike ALL other types of fins, with the split fins you feel your muscles straining to slice the fin through the water.
This is where the Force fins comes into play. The Force fin in my opinion is what would happen if a Split fin and a Jet fin had a baby. The Force fin provides effortless flutter kicks for a high amount of thrust. Additionally it slices through the water like a hot knife into butter. You literally feel like you don’t have fins on, whether you’re flutter kicking or slicing the fin through the water side-side. Even better, it allows for quick bursts of speed at no effort at all, something I was incapable of doing with the Split fin.

So it goes without saying that if you have weak ankles or legs and can’t even take the strain from a flexible blade fin, you should go for a Force Fin over a Split fin. The Force fin is the epitome of effortless, no matter how you move your fin through the water. It’ll allow you to have an effortless flutter kick, an ability to gain quick bursts of speed at no effort (something I have yet to see another fin copy), and it allows you to perform specialty kicks, which you must have if you want to be an effective diver.

Going off on a side note, specialty kicks allow you to move in nearly all directions. If you’re a photographer, a cave/wreck diver, or someone who doesn’t want to crush coral, you have to have specialty kicks down to do your dive effectively. There will be a time when you can't kick forward and away from an object without touching or crushing it. You’ll need to either back kick away or helicopter turn to face a new direction quickly without adding more forward momentum.

So I know Force Fins are ridiculously priced, but if you have a choice between Splits and Force fins, I’ll have to say go with the Force Fins.
I’m now jumping onto the “I dislike Split Fins” boat with a legitimate excuse. I do not like how highly specialized they are.

Breakdown
Flutter Kick Energy to Thrust Ratio (low-high) – you want a low ratio to get a lot of thrust for little energy/effort spent
Force Fins, Jet Fin, Split fins, Blade Fins
*Jet fins beat Blade fins only when you do a kick-glide-kick method; else you get tired faster with Jets than with Blade fins and the situation becomes moot*
*Jet fins beat Split fins because you’re able to go further and faster with a kick-glide-kick method than with any kick method used with Split fins*
*If you have weak ankles or leg muscles then Jet Fins WILL be placed at the end of the list no matter how you kick with them*

Specialty Kicks - Back kicks, Helicopter Turns, Frog Kicks
Ease of Performance (easy to hard) – ability to perform this kick with little effort, frustration, or strain
Jet Fins, Blade, Force Fins, Split Fins

Effectiveness of Sp Kicks (high to low) – distance covered per amount of effort/frustration expended; high indicates more distance covered with little frustration or concentrated effort
Jet Fins, Blade, Force Fins, Split Fins
*Split fins were not effective in back kicks at all*

Durability (more durable-less durable) – strictly from a touch and sight opinion
Force Fins, Jet Fins, Tie (Split, Blade)
- Force fins are made of a thick plastic-like material, which would take some heavy shears to cut through.
- Jet type fins are made from either black rubber or a polymer, which is kinda soft yet sturdy.
- Depending on the specific model, you can find Split fins that feel more durable than flexible blade fins (and vice versa). However I think plastic stiff blade fins will beat out most split fins.
*This is all assuming you take good care of your fins, i.e. normal wear and tear; minimizing sun and salt damage*

 

[g1138]

Questions, Comments, and Rebuttal Opinions are greatly encouraged.

But PLEASE limit the debate so any new members or beginners can get a voice or break through the static.

State you opinion but don't go off against someone else, at least on this post.

Thanks!

 

[mjr0112]

Nice review, I use split fins and love them. I don't use them for the fact that I feel there better than all others, but for the fact I have problems with my ankles. When I use paddle type fins, I find myself thinking about how my ankles hurt and not the dive itself. I use Apollo Bio fins, and it takes all the stress of my ankles, and I can enjoy my dive.
I do feel my speed is just as good if not faster with my split fins once I get going, they do lack that "thrust" on take off as compared to my paddles, and in current, my split fins fall short.

 

[k ellis]

The Force fin provides effortless flutter kicks for a high amount of thrust. Additionally it slices through the water like a hot knife into butter. You literally feel like you don’t have fins on, whether you’re flutter kicking or slicing the fin through the water side-side.

I take it you have not tried the Apollo Bio fin yet.

There is a reason why there are so many types of fins on the market and one reason there are so many is people view them kind of like they do cars. One person will swear up and down Chevys are a piece of crap while Fords just cant be beat and then youll find another person who has a totaly opposite opinion.

In Short I have 3 diffrent types of fins and found 2 of those type to be very useful for totaly diffrent scenarios. While the Apollos are by far some of the most incredible fins I have used to date they are a split fin and splits in currents are not a top of the line choice. In this instance I use my Aqualung slingshots which excel in heavy currents.

Split fins are kind of more like a standard shift sports car. They can do quiet a lot of things the blade fins can do you just have to multitask at first while adjusting to the diffrences. Once you get used to a good pair of splits youll usually find them just as easy to use as blades.

Now again there are reasons people pick particular types of fins for particular types of diving. I am no tech diver but have heard many say for what they do splits are woefully inadequate and this seems to be backed up by the fact I can not honestly say I have witnessed any tech diver use splits.

 

[Quero]

I started out with split fins, and I learned all my specialty kicks while wearing splits. Then I switched to paddles so that I could fin backwards more easily. It's true that the techniques for specialty kicks are harder to master with splits than with paddles, but with a few limited exceptions, such as back kicking, I have found the performance of split fins reasonably similar to paddles in virtually all dive conditions. I tend to think that people who start out with splits and then adopt paddles have little trouble adapting their kicking technique, meaning that these divers can use either type of fin to good effect. But from what I've heard people say about switching from paddles to splits, it's not an easy transition at all, and most of these divers simply give up on splits and never really learn to dive them effectively.

Therefore, I am always mindful of the transition issues when I read comparative reviews of split vs paddle fins written by people who started out with paddles. I'm not convinced that the conclusions in the review are entirely valid because I do think there is assessment bias that comes from the challenges of switching from paddles to splits as opposed to the other way around, especially when the review is based on a single trial during which it is questionable that the researcher has had time to master the subtleties of technique needed to make split fins render the desired results.

 

[Rich Keller]

Nice review, I use split fins and love them. I don't use them for the fact that I feel there better than all others, but for the fact I have problems with my ankles. When I use paddle type fins, I find myself thinking about how my ankles hurt and not the dive itself. I use Apollo Bio fins, and it takes all the stress of my ankles,in and I can enjoy my dive.
I do feel my speed is just as good if not faster with my split fins once I get going, they do lack that "thrust" on take off as compared to my paddles, and in current, my split fins fall short.

I just started using Scubapro twin jet fins last year because they are easier on my knees then the paddle type fin. I have not noticed any drop off in performance.

 

[g1138]

All valid points. I think the fact that Split fins were the las major type of fin for me to try swayed my opinion somewhat. I had a hard time adjusting to it, and definitely didn't get as long an exposure as I would have liked to. My friend actually requested her Splits back early because she couldn't take the weight of Jet fins.

I'll have to ask k_ellis, do you feel any resistance when sweeping your fin sidways through the water?

 

[scubafanatic]

+1 for the Apollo Bio fins with SS heel straps! Although I actually prefer the 'regular' stiffness version, if one wants a stiffer feel, Apollo offers the 'XT' version (extra torque) which are substantially stiffer feeling than the regular version. I've got 4 pairs of the regular version, and 1 pair of 'XT's, and I was surprised at how much stiffer they felt on the ankles.

 

[TSandM]

My friend actually requested her Splits back early because she couldn't take the weight of Jet fins.

Interesting! I know the first time I put on Jets, I thought the Mafia had put me in concrete boots and were trying to kill me. But in one of our recent OW classes, we had a pair of students, one in a Jet fin knockoff and one in splits. They traded fins in the pool for fun, and neither of them wanted to use the split fins after that

I started in splits, went to Jets, and have had one or two occasions to use splits since the change. I pretty much agree with the review -- the problem with splits is that it's almost impossible to slice them through the water without resistance, and the scooping motion required for a good back kick is far less effective (although I was able to move backwards better than described here). There is no question that they reduce leg stress, though.

 

[DevonDiver]

+1 for the ................... (*insert name of fins that you wear).









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