DIR fin technique questions

[Lenaxia]

Hey SBer's,

My last two dives I spent working on DIR style kicking and found that, yes, they do reduce silt kick up significantly. I was able to reduce my silt to zero even when cruising inches from the ground.

I am curious on a few things though:

1) Why do people use the frog kick even when traversing open water well above the bottom? As a former competitive swimmer, frog kick is the most inefficient kick of all three because of the repeated fast acceleration and fast deceleration. Even the DIR style flutter kick with 90* bent knees is much more efficient.

Not just in open water but through kelp forests too. I watched as both of my experienced buddies this weekend frog kick through kelp forests and couldn't help but notice that if for instance kelp snagged on their tanks, the fast acceleration from frog kick would pull them upwards, or otherwise worsen things by pulling tighter. Whereas when I switched to DIR flutter, if something snagged, it would be gradual and I could quickly untangle without as much thrashing around as frog produces.

I can see frog kick's utility when maneuvering in smaller areas but not for longer distance travel or even cruising at depth.

2) Again, as a competitive swimmer, frog kick is really hard on the knees. Those of us who used to race the stroke can attest that long workouts of breaststroke did not leave us with happy knees. While I don't have bad knees yet, I'm expecting some in a couple of years due to rowing injuries. Does DIR actually address this or is it just a HTFU issue for them?

If you do have bad knees, how do deal with frog kick? Or do you just not do it?




In the end, I just don't see the heavy emphasis on DIR frog kick being correct or necessary. Yes, it is a kick that has uses and should be used should the situation call for it. But to use it as a primary mode of movement? It seems impractical.

 

[fnfalman]

In the end, I just don't see the heavy emphasis on DIR frog kick being correct or necessary. Yes, it is a kick that has uses and should be used should the situation call for it. But to use it as a primary mode of movement? It seems impractical.

Because you ain't cool unless you frog kick all the time.

Most people, be they DIR or recreational divers, don't bother to put a lot of thoughts into scuba. They take everything they're taught as gospel.

 

[Rainer]

First, the frog kick used in diving is not the same as that used in swimming. To me, it seems *much* less harsh on the knees. Even after long dives frog kicking, I've never experienced any knee pain. Are you sure you are doing it correctly? You might want to meet up with a GUE or UTD instructor for pointers.

Next, the main reason you'll see many DIR divers rely on the frog kick as their standard kick is because it's efficient from an energy perspective. You give a slow kick, then glide, recover, and kick again. It's simply not tiring. You can do this for hours. I can't say the same about a constant flutter (for which admittedly, you can also always stop and rest, but then, you're not making any forward progress). When just cruising a reef or wreck, I'm not looking to move fast; the frog kick works very well. In any case, I don't find my usual "cruising" frog kick to involve a fast acceleration (positive or negative).

If you do need to move fast or fight heavy current/flow, the frog kick certainly is not ideal (due to the recovery stroke). In such cases, a strong flutter is best (and can still be done as a non-silting kick). In tight kelp or when in contact with a teammate, a large frog kick is also not ideal. A small modified frog or modified flutter is probably a lot better if you don't want to make contact with anything outside of your body width.

DIR teaches many fin kicks. Not all are appropriate for every scenario. Part of what is taught is when to make use of each kick.

Hope that helps.

 

[DBailey]

YouTube - Frog Kick

Is this the frog kick you are thinking of?

 

[Blackwood]

1) Why do people use the frog kick even when traversing open water well above the bottom? As a former competitive swimmer, frog kick is the most inefficient kick of all three because of the repeated fast acceleration and fast deceleration.

How are you quantifying "most inefficient"?

My gas lasts much longer when I frog kick than when I flutter (modified or otherwise).

Personal swimming anecdote:

I swim for exercise (not competing), and if I pull out a kickboard and make a quasi-frog kick (it's not really the same thing since I'm not submerged) and look over at the lane markers, I cover about one color section per kick cycle. Switching to any form of scissor kick or flutter kick, I have to kick about 7 times to cover the same distance. If I really hit it hard I can go faster, but my endurance attests to that requiring substantially more energy. Speed wise, dolphin kicking (i.e. "butterfly") is my fastest and most distance efficient (distance covered per kick cycle), but also the most tiring.

 

[NC Wreck Diver]

I swim fast..........I just can't help it. Even before diving, as kids we were in the pool everyday. So swimming is second nature to me. Even though you don't 'swim' in diving (just finning), I end up ahead of my buddies, stopping and waiting.

I have taken off 65 pounds in the past months. With that, I've tried to work on my legs and get back into decent shape. So the treadmill work for me has helped.

Back to your OP........

1). I frog kick in open water to slow down and stay as a group with my buddies. All of them have good experience, and can keep up with me if they want to. But I don't want to piss them off. Also, I even get a better SAC rate with a slow frog kick (mine is OK with a strong kick, but even better with a slow frog kick).

2). I spearfish. A good frog kick (or one snap of my blade fins), puts me down the bottom of the wreck without kicking up silt, and spooking the fish. It works well.

I'm sure many other divers have plenty of other different reasons to frog kick, but there is my .02.

 

[Roko]

I wouldn't worry too much about "DIR Kicking" vs "Non-DIR Kicking". I'm not a DIR diver, but I frog kick almost exclusively...

I find scuba-style frog kick much more efficient, natural and relaxing than flutter kicking... I suppose I should mention that I'm also a former competitive swimmer. As mentioned above, swimming frog-kick and scuba frog kick are not quite the same. Once I got the hang of the proper way to do it while diving, I found I vastly prefer it to flutter kicking..

Plus not silting up helps a lot, I find, since most of the cool stuff is on or near the bottom.

 

[Lenaxia]

YouTube - Frog Kick

Is this the frog kick you are thinking of?

Yes this is the frog kick that I'm referring to.

For reference, this is the flutter that I'm referring to:

YouTube - The Flutter Kick

@Rainer:
The DIR flutter kick isn't fast either. It's a very slow kick and requires less energy and no weird angles on your legs.

I haven't done too much research into DIR, I had just been trying things that I had heard discussed by other people. If they do indeed teach situational kicking then that makes more sense. I just haven't seen it been exercised much with the people I dive with and the videos I have seen.

I wouldn't worry too much about "DIR Kicking" vs "Non-DIR Kicking". I'm not a DIR diver, but I frog kick almost exclusively...

I find scuba-style frog kick much more efficient, natural and relaxing than flutter kicking... I suppose I should mention that I'm also a former competitive swimmer. As mentioned above, swimming frog-kick and scuba frog kick are not quite the same. Once I got the hang of the proper way to do it while diving, I found I vastly prefer it to flutter kicking.

I guess one thing I didn't consider was the type of fin used as well. I am unfortunately unable to use Jet fins because of the way they rub my feet so I am using blade/split fins. I can understand that frog kick doesn't work as well with these kinds of fins.

 

[Rainer]

@Rainer:
The DIR flutter kick isn't fast either. It's a very slow kick and requires less energy and no weird angles on your legs.

Having done several "DIR" courses (and having dived "DIR" for several years), I have a good sense of what a "DIR flutter kick" looks like. I assure you, you can move pretty quickly if you need to.

I haven't done too much research into DIR, I had just been trying things that I had heard discussed by other people. If they do indeed teach situational kicking then that makes more sense. I just haven't seen it been exercised much with the people I dive with and the videos I have seen.

Trying to learn about DIR on the internet is often a good start but will always come up shorter than doing a proper course or diving with those who have some good formal training. The videos are all overly exaggerated and don't cover their situational use nearly as well as a course or proper mentor would. If your "DIR" friends are doing big frog kicks through thick kelp, I'm guessing they aren't very DIR... (it's the wrong kick for that job). The Bay Area has many experienced DIR divers and instructors. I'm sure many would be happy to go over kicks in person.

Good luck!

Edit: Just noticed your addition about what fins you're using. Yes, it does matter. These kicks are all easier in stiff paddle fins.

 

[JamesMottUTD]

The menu of DIR propulsion techniques are there for the diver to make a logical decision on their method of travel underwater and to have different options for different situations and environments. In some places the modified flutter is the preferred choice, sometimes it might be a scooter!
If done correctly, the frog kick should be one of the lowest impact, least taxing and most efficient forms of underwater propulsion. You should not experience repeated fast acceleration and fast deceleration. Instead, a smooth and consistent form of travel that uses the smaller muscles of the lower leg should provide you with a power stroke that allows you to glide through your body’s natural slipstream, easily with little exertion.
The development of a proper frog kick requires critical evaluation and guidance from a knowing instructor or mentor, not to mention repeated practice. This skill development will give you the ability to reduce silting when near the bottom, but also to compartmentalize muscle groups, decrease effort, minimize CO2 buildup, reduce your workload and gas consumption, and enjoy your diving more.
Snagging on kelp, thrashing of any kind and pain the knees or any other area should be seen as a sign that something bigger is missing in the overall performance of the technique, awareness underwater and understanding of the environment being dove.
James Mott
jm@unifiedteamdiving.com
Unified Team Diving