Pool Blackouts; what do they look like?

[anthropisces]

I have been trained to recognize a diver in trouble (samba-ing, blacked-out, blue-lips, etc.) through Fii. That training focused on a diver coming up from depth.

Lately I'm pool training, dynamics, with a buddy, to help increase my abilities in the sea. We train in a lap pool, only four feet deep.

What kind of trouble can we get in? Are black-outs caused by the same phenomena as those occurring as a diver comes up from depth? Should black-outs be treated just as they are when a diver coming up from depth?

Also, I've been hesitant to push myself in the pool (I'm barely making 75 meters) because I don't know how to approach these safety issues.

When is the right time to come up for a breath? I'm pretty good at pushing well into discomfort but I'd prefer not to black out. What signs should I look for to let me know that its time to surface?

 

[Rik]

Pool black-outs and depth black-outs differ from each other from their initial cause. Depth black-outs are caused by sudden hypoxia caused by the drop in the (partial) pressure, while pool black-outs are caused by a more gradual occurring hypoxia, its onset depends on how fast oxygen is being burned and what the individual freediver is doing. For example, static apnea versus dynamic apnea with an monovin.

Therefore, in most cases, you can see clear warning signs as buddy before the actual black-out would occur. Signs of of an impeding or acute black-out would be: release of air, confusion, changes in swimming style, bad turns, jumping lanes, etc. etc. There are several clips on youtube who can give you an idea how this would look.

There is however, one aspect that is importantly different from depth diving. With depth, you have the freediving swimming towards the surface at an given spot. In other words, you do know where he or she is heading to, and where they would surface.

In dynamic apnea, unless you are training with fixed distance and goals, you wouldn't know where someone would or could surface. This means that you, as a buddy, needs to be close to the freediver at all times. This would ask for a slightly different buddy technique. Of course, the best thing is to practice this together with an freediving instructor, knowledgeable in the subject.

There are different methods how to achieve longer distances in dynamic apnea. Trying to improve your personal best every time you train should be discouraged.

The basis of achieving better distances is due improving your swimming technique. The next step is to train yourself to perform through the various training tables that do exist out in the wild. Again, while there is a lot of information on the forum, a freediving instructor with knowledge on this subject could help you to get the best results.

 

[Kars]

In addition to Rik's comments and recommendations, considering he's an instructor, I'm not (yet), a few more idea's.

Practice your rescue abilities in the pool, in static and in dynamic.
To safe energy buddying you can walk along the side, where the diver swims along the wall. An approach that is only second to swimming along. Consider that staff and pool owners NEVER want to see a BO. Training for this maybe received with mixed feelings of respect and fear for what you maybe up to.

From your reading your post I feel you may feel uncertain about this unknown area from swimming comfortably until samba.

My suggestion is to practice statics; dry and wet - with buddy -, and learn how it feels, what your signs are. Gradually exploring.

Some examples of approaching your limit are: inability to hold breath (hehe), inability to count/think, trembling, tunnel-vision (seconds before BO).

Exploring your limit's is a tricky job, preparation, form of the day, circumstance, stress all change all the time.
Personally it took me years to get some bearing on my limits, crossing them in too many events. Contrary to competitions I had only a few BO's in 8 years of training.

CO2 clouds your mind and perception, therefore avoid hyperventilation and try to get and keep your HR low. I find it amazing how clear my mind is during FRC diving, once them physical discomfort is overcome.

I'm looking forward to other peoples responses, excellent questions!


Love, Courage and water,

Kars

 

[Phil C]

"CO2 clouds your mind and perception" Kars, do you mean Hypoxia clouds your mind and perception?

Phil C

 

[Kars]

Both, CO2 and Hypoxia, and for depth you can add N2 too

All have different feelings and special effects