Breathing technique

[Angelo Farina]

There are many people here who are saying to not retain your breath and to breathe normally.

This is what most training agencies suggest to us (instructors) to teach to our students.
Which of course is plainly wrong!
Still there is a number of good reasons suggesting to use this approach (which technically is wrong, as You just discovered). I try to explain you some of these reasons:
1) Commercial: 40 years ago, there was just ONE diving course, lasting 9 months, with hundredths hours training, where the student was learning EVERYTHING, including deep diving with multistage deco and pure-oxygen rebreathers. Only 10-20% of people could complete such course.
Then PADI arrived, fractioning the whole training in vary small chunks, making it possible to become a scuba diver in a few days, with very limited knowledge and skills, but already enjoying it. And then inventing several dozen of further courses, specialities, etc. With such an approach it is entirely wrong to teach advanced breathing control during the first 3-4 of these courses, better to leave this for high-end courses, as many other useful skills (trim, buoyancy, kicking, etc.). Each of them can be another course, with more money for the instructor/PADI. Why giving it for free at the first course?
2) Safety: the most dangerous thing which can happen to a new-come scuba diver is to emerge very quickly without exhaling. This can cause lung rupture and traumatic embolism, with fatal consequences. This is both very dangerous and relatively easy to happen, so for the instructor it is perceived as a very severe risk. Anything going in the direction of increasing this risk is better avoided. And teaching to hold the breath while scuba diving goes definitely in that direction. So better leave the student to consume a lot of air, breathing inefficiently, but reducing the risk of lung damage. At the end of the dive he will have a terrible headache due to CO2 retention, but this is not dangerous... And it is HIS headache, not mine...
3) Time: teaching breathing control takes a lot of time, and requires a lot of concentration from the student. It is faster and simpler to tell him to "breath normally" and avoid the problem entirely... Better to spend the little available time for teaching the "mandatory" skills required by the certification agency for being able to release the cert card.

I am sure there are at least a couple of other very good reasons for not teaching the correct breathing control technique to new-come scuba divers.
But here on SB, I think that also instructors should reveal the truth, when questioned, albeit we routinely do not teach this to our students, for the reasons explained above.

 

[Sbiriguda]

I need to find a video of my wife using it. I did not find any video on youtube showing it...
View attachment 559969

If you or any other can post a video of this technique I am very interested
I find only horizontal scissor kick exercises videos by gym trainers... still, they oddly seem to show the same movements you describe for scuba
1) WRONG MOVEMENT - ONE LEG ON TOP OF THE OTHER as per @BlueTrin 's post

2) CORRECT MOVEMENT - BOTH LEGS AT THE SAME LEVEL as per @Angelo Farina 's post

Is the second video showing the right movement to be applied in scuba?

@Angelo Farina
Thanks for your very useful interventions in this discussion, one of the best I have read on this topic

 

[Angelo Farina]

Is the second video showing the right movement to be applied in scuba?

In scissor kick (either horizontal or vertical) the legs never cross.
So the second video is OK in the initial part. Then it becomes wrong.
Of course the rotation of the fin blades is missing in this video...
And usually underwater one is facing down, not up.

 

[Ayisha]

(From TDI)...Relax and focus on your breathing, with extra attention on the exhalations. Make sure you are ridding your body of all of the built up CO2, and you will see a drastic improvement in your air consumption."

The above is exactly right. When I was a new diver, I had to concentrate on slowing down my breathing and exhaling fully. A side effect was my improved gas consumption. I still find myself concentrating sometimes when in current, etc.

Dr Lynn Flaherty (may she RIP) used to advise that we exhale fully to empty the carbon dioxide from the lower third of the lungs. It's sound advice and it works really well.

 

[Angelo Farina]

So you move the fins horizontally out on the plane then incline and clasp without bending the knee ?

YES

Is that more efficient for longer distances than a flutter ?

Absolutely NO.
Nothing surpasses the efficiency, power and thrust you get employing your freediving fins the way they are designed, in a vertical, ample and fluid flutter movement, as in this photo. Please note that the legs are perfectly extended and that both the upper and lower face of each blade is actively pushing water to the rear.
Also note the position of the arms, which are attached each other and perfectly in line with the body and the head

This is what I (and my wife) used to teach when preparing athletes for finned swim competitions.
Compare the image above with the bad trim and bad kicking usually taught to students of "tech diving" courses:

You see that the legs are flexed at almost 90 degrees, the arms form a relevant angle with the direction of propulsion (causing a lot of drag) and of consequence the propulsion will be much less efficient than the proper flutter shown in the first image. Also the body is not truly horizontal, as the diver is looking forward, not down.

So, why these inefficient methods of kicking were developed (and promoted here on SB)?
The horizontal scissor kick was developed for similar reasons as the frog kick: for avoiding to hit with fins where they could cause damage.
The frog kick is for avoiding hitting the bottom (muddy), the horizontal scissor kick is for avoiding hitting the ceiling, inside caves, where coral grows. You cannot use standard or modified frog kicking in these caves, as the legs and fins are kept much higher than the cylinders (as in the second photos above), they will hit the ceiling of the cave destroying the coral.
Both frog kick and horizontal scissor are efficient just around 40-50 % of a proper flutter kick..
Horizontal scissor is a bit more efficient than frog kick, as the legs are in line with the body, knees not flexed, and the arms are usually kept attached to the body, not partially stretched as in the second image, causing less drag.
It must also be said that doing a proper flutter kick is not that easy. Many scuba divers cannot flutter correctly, they flex their knees or keep ankles in hammer position, using bicycle kick, which is even less efficient, around 20%.
Here you see bicycle kicking:


The difficulty in performing a proper flutter kick is the reason for which many instructors, who do not come from years of freediving, or are not finned swim instructors, and perhaps are not mastering themselves a proper flutter kick with long fins, teach to their students frog kicking: it is still better than bicycle, and a bit easier to learn than a correct flutter...
The horizontal scissor kick is even less usual, being taught only to cave divers entering these special caves full of red coral, here in Italy (red coral grows only here and in Japan).

Sorry for the long OT: as already said, kicking technique has little relationship with breathing control (albeit instead bad kicking makes your SAC to explode, if you need to swim against current, as you need to exert much more effort for a given thrust).