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For static apnea, I think they're talking about laying on the surface of a shallow pool with a spotter standing next to them. The free diving--where they do thi

For static apnea, I think they're talking about laying on the surface of a shallow pool with a spotter standing next to them. The free diving--where they do this at depth--is what kills people.

jobigoud 9y ago
I'm curious, what does the spotter do? How does one know there is a problem? I assume at high levels the competitors are able to lower their metabolism and heart rate, etc. What are alert signs, are they monitoring brain activity?
- mogoman 9y ago
  Generally you lie in the water in a wetsuit for buoyancy. The spotter holds on to you to make sure you don't float out to sea (in our case). They also check on you by prompting you to give an "okay" indication (by lifting a finger every 30 seconds or so). One danger of being under water is that you can pass out even after you've taken a breath of fresh air, so the spotter also is there to make sure you are good in the few seconds after you come up.
fabrice_d 9y ago
What kills people is inadequate security measures, not depth diving vs. static apnea in a pool. There have been very few (I think only one) deaths during freediving competitions, where protocols are used to guarantee the security of the athletes. Remember that you don't die of a black out, you die of drowning because you inhale water during a black out. As said in another comment, the black out is a protective mechanism when you run low on oxygen, but the breathing reflex is triggered by high CO2. Freedivers train both to sustain low oxygen (by doing long breath holds) and high CO2 (by doing repeats of shorter ones). Monitoring a static apnea is pretty simple if you just pay close attention: when a black out happens, the diver will usually release a lot of air for instance, and pulling them out of water before they drown is what you do. Then you slap them to wake them up :) In open water competitions, these days divers are tethered to the dive line, announce their target depth and can't go past it. They also announce an expected dive time which is used to plan the start of the safety divers. These safety divers escort the athlete on the end of the dive up (sometimes, as deep as from 30m), staying close enough to grab them if needed, but never touching them (that would disqualify as assistance). There is also a counter weight in place to bring up everything quickly in case something goes wrong deep. Issues are usually happening close to the surface (let's say in the last 10-15m); deep blackouts are very rare and usually a consequence of other problems like being disoriented if you get a ruptured eardrum. Recreative freediving is a wonderful activity with very little risk if you just use a buddy system and don't push the limits beyond what both of you can do. It's good for you body and your mind!
- YeGoblynQueenne 9y ago
  The problem is that you can't hold your breath if you black out. So if you black out while submerged you're in grave danger, even more so if you're some 30m down (then you're as good as dead). Even if you have a buddy while this happens and they manage to grab you and drag you out instantly, then start CPR the moment you're on the surface there's nothing guaranteeing you're going to survive.
  - apetrov 9y ago
    Actually the rescue procedure is straightforward https://www.deeperblue.com/rescue-procedures-for-freediver-black-out/ https://www.deeperblue.com/rescue-procedures-for-freediver-b... so if there is a trained buddy watching your back you gonna be fine. PS you don't need CPR to recover from blackout.
    - YeGoblynQueenne 9y ago
      That link literally says exactly what my comment says. That if you black out on the surface, then, OK, but if you black out in the water then laryngospasm will protect you from inhaling water for a bit (under a minute), but then it will end, at which point you'll inhale water and CPR will become even harder. etc. etc.
      - fabrice_d 9y ago
        Sure, but if you have a buddy, a minute is more than enough for a rescue. I did it a couple of times from about 10m and it is a bit stressful but I got free beers in the end :)
        YeGoblynQueenne 9y ago
        Sounds like fun. Maybe drown-and-get-rescued should be introduced as a new sport.
      - YeGoblynQueenne 9y ago

For static apnea, I think they're talking about laying on the surface of a shallow pool with a spotter standing next to them. The free diving--where they do this at depth--is what kills people.

jobigoud 9y ago

I'm curious, what does the spotter do? How does one know there is a problem? I assume at high levels the competitors are able to lower their metabolism and heart rate, etc. What are alert signs, are they monitoring brain activity?

mogoman 9y ago
Generally you lie in the water in a wetsuit for buoyancy. The spotter holds on to you to make sure you don't float out to sea (in our case). They also check on you by prompting you to give an "okay" indication (by lifting a finger every 30 seconds or so). One danger of being under water is that you can pass out even after you've taken a breath of fresh air, so the spotter also is there to make sure you are good in the few seconds after you come up.

fabrice_d 9y ago

What kills people is inadequate security measures, not depth diving vs. static apnea in a pool. There have been very few (I think only one) deaths during freediving competitions, where protocols are used to guarantee the security of the athletes. Remember that you don't die of a black out, you die of drowning because you inhale water during a black out. As said in another comment, the black out is a protective mechanism when you run low on oxygen, but the breathing reflex is triggered by high CO2. Freedivers train both to sustain low oxygen (by doing long breath holds) and high CO2 (by doing repeats of shorter ones). Monitoring a static apnea is pretty simple if you just pay close attention: when a black out happens, the diver will usually release a lot of air for instance, and pulling them out of water before they drown is what you do. Then you slap them to wake them up :) In open water competitions, these days divers are tethered to the dive line, announce their target depth and can't go past it. They also announce an expected dive time which is used to plan the start of the safety divers. These safety divers escort the athlete on the end of the dive up (sometimes, as deep as from 30m), staying close enough to grab them if needed, but never touching them (that would disqualify as assistance). There is also a counter weight in place to bring up everything quickly in case something goes wrong deep. Issues are usually happening close to the surface (let's say in the last 10-15m); deep blackouts are very rare and usually a consequence of other problems like being disoriented if you get a ruptured eardrum. Recreative freediving is a wonderful activity with very little risk if you just use a buddy system and don't push the limits beyond what both of you can do. It's good for you body and your mind!

YeGoblynQueenne 9y ago
The problem is that you can't hold your breath if you black out. So if you black out while submerged you're in grave danger, even more so if you're some 30m down (then you're as good as dead). Even if you have a buddy while this happens and they manage to grab you and drag you out instantly, then start CPR the moment you're on the surface there's nothing guaranteeing you're going to survive.
- apetrov 9y ago
  Actually the rescue procedure is straightforward https://www.deeperblue.com/rescue-procedures-for-freediver-black-out/ https://www.deeperblue.com/rescue-procedures-for-freediver-b... so if there is a trained buddy watching your back you gonna be fine. PS you don't need CPR to recover from blackout.
  - YeGoblynQueenne 9y ago
    That link literally says exactly what my comment says. That if you black out on the surface, then, OK, but if you black out in the water then laryngospasm will protect you from inhaling water for a bit (under a minute), but then it will end, at which point you'll inhale water and CPR will become even harder. etc. etc.
    - fabrice_d 9y ago
      Sure, but if you have a buddy, a minute is more than enough for a rescue. I did it a couple of times from about 10m and it is a bit stressful but I got free beers in the end :)
      - YeGoblynQueenne 9y ago
        Sounds like fun. Maybe drown-and-get-rescued should be introduced as a new sport.
    - YeGoblynQueenne 9y ago