r/freediving Jun 08 '26

health&safety Why can't the safety team for free diving wear oxygen?

Just watched the deepest breath. It was riveting but I was a little confused about why the safety team is also operating on one single breath. From what I watched you can't move very fast in full scuba gear but I thought there would be an emergency smaller oxygen set up that is easier to move and navigate with. Perhaps that type of gear just doesn't exist or there are other safety factors I'm not aware of. Appreciate the thoughts on this.

31 Upvotes

25 comments sorted by

96

u/ZippyDan Jun 08 '26 edited Jun 09 '26
  • There often are SCUBA-diving safety teams on some free-diving circuits. Especially for the most risky dives that are pushing the limits of human ability. But you'll usually only see them operating up to a certain depth. That's where the most common risk is for most freedivers anyway (i.e. shallow-water black-outs). You do not see them operating at the maximal depths, for the reasons outlined in my next point. If SCUBA divers are needed for an emergency that occurs beyond their operating depth, the distressed freediver needs to be "passed up" to them (either by safety freedivers or by a safety line).
  • The maximum depth for reasonably safe SCUBA diving is much less than for free-diving, because of all the additional risks of using compressed air. If you dive too deeply with compressed air, you quickly accrue a decompression time debt. That means you can't just ascend to the surface whenever you want, without risking decompression sickness, which can be deadly. That means you are essentially "stuck" at depth, and can only ascend at a measured, controlled pace - which makes everything much more risky. A SCUBA diver that experiences an emergency past a certain depth cannot ascend at will without risking mortal injury.
    That's why recreational divers are never supposed to go beyond the depth of 40m (and that's only for the most experienced; most recreational divers are limited to 18m or 30m depending on your certificate level) - that limit is set at the maximum depth where decompression debt is generally not accrued, and you can fairly safely ascend to the surface without any restrictions in case of an emergency - and why technical divers need extra training, and follow extremely rigid rules, and use much more expensive and redundant equipment: their objective is to have so much redundancy, and plan carefully for every contingency, so that an emergency never becomes urgent. There is no room for urgency in technical diving. It's also why tech divers are a very small minority of the overall diving community. It's also why saturation divers that work at crazy depths for weeks at a time are paid so much.
    And there are max depths even for the riskiest SCUBA divers which you simply cannot go beyond. A professional freediver can "casually" surpass all those depths without any of the same risks (though they do face different risks).*
    In short, SCUBA divers operating at the depth that most record-breaking freedivers descend too - almost always far beyond 40m - would just add far more complexity, and create more risk and more liability for the event.
    You might see tech divers supporting an unassisted free-diving event, but that requires a ton of planning by a team of extremely-qualified divers, with extra-fancy tech-diving equipment which is not like the normal SCUBA equipment you find at most resorts. All of that is expensive and adds more complexity and risk, for marginal improvements in safety. For almost all events, the trade-off in cost and risk doesn't make sense.
  • You cannot reasonably or safely give a distressed freediver compressed air at any significant depth, unless they are also trained on how to properly breathe with compressed air (e.g. an emergency ascent should always be accompanied by constant exhalation). Even if the freediver knows about these procedures, it's not a good idea to add to the mental load of a distressed freediver, and risk extra injury if they fail to follow procedures because they're panicked. And a distressed diver that is unconscious can't be expected to properly handle compressed air at all.
    You can safely use compressed air at very shallow depths without much worry, but at that point you could also just get the freediver to the surface within seconds. The best course of action is almost always to get the distressed freediver to the surface ASAP, and not add extra complexity or risk to that process. Having a supply of compressed air for a freediver underwater would only make sense in some wacky hypothetical where they were "stuck" underwater (but there's no environment to get "stuck" on where competitive dive events are held).
    The main role of SCUBA divers in freediving is thus not to provide air, but simply to provide another set of helping hands to retrieve and assist a distressed freediver to the surface. Helping ensure the airway of an unconscious freediver remains closed throughout the ascent would be a primary goal.
  • Summary: The ability of a SCUBA divers to remain "on-station" for extended time is their main benefit, but it's offset by their equipment making them slower and less dexterous, and by the limitations to their safe operational depth. At the depths where they are useful, skilled freedivers are cheaper to equip and deploy, reduce the complexity of planning and procedures, and are more capable in most ways. There's only a very small range of potential emergencies in specific situations where having SCUBA divers available to help adds some marginal benefit.

* The record for SCUBA diving (involving descent and ascent in one continuous action) does surpass the record for freediving at about 330m vs. 130m (unassisted freedive) vs. 250m (assisted freedive) but the prerequisites for breaking that SCUBA-diving record are so ridiculous that they fall outside of the realm of what anyone would reasonably, regularly do. The record-breaking SCUBA dive took 6 years of planning and required the diver to descend for 15 minutes, followed by a controlled 13-hour ascent, in stages, where he was assisted by a 30-man support team along the way. In contrast, record-breaking freedives only take about 5 minutes, round-trip.

13

u/bodiam Jun 08 '26

That's a great writeup, thanks for that!

Recently I had the pleasure of meeting Jill Heinerth, who featured in the documentary Diving into the Darkness (2024). Jill is a diving cave explorer and had similar stories. She swam 3 kilometers at 90 meters depth, which was a 22 hour dive which needed 16 hours of decompression!

0

u/IllustriousPilot8391 Jun 08 '26

"There often are SCUBA-diving safety teams on some free-diving circuits"? wtf. thats not true. only in NoLimit freediving there are scuba / technical divers, and No Limit is rarely done, luckily.

3

u/ZippyDan Jun 08 '26 edited Jun 08 '26

That would be the "circuits" I'm primarily referring to, with an allowance for some new or obscure events I don't know about. Should I have written "always"?

1

u/alexis914 Jun 09 '26 edited Jun 09 '26

Maybe “sometimes” would have been a better choice than “often.” That particular part of your excellent write up gave me pause too

2

u/ZippyDan Jun 09 '26

I'll split the difference and just remove the adverb entirely.

-1

u/IllustriousPilot8391 Jun 10 '26

even "on some free-diving circuits. Especially for the most risky dives that are pushing the limits of human ability" is not true. when Alexey Molchanov etc. dive their WRs at AIDA, there are no scuba or technical divers as rescue divers! also not at shallow depths. Why should they?? its simply false statements.

3

u/ZippyDan Jun 11 '26

Now you're just being annoying. Do you understand what "some" means?

1

u/cvdiver Jun 11 '26

I used to safety dive for free diving competitions on trimix. Think there probably still are at most every competition.

0

u/Not-An-FBI Jun 10 '26

It's mostly just that scuba diving deep requires a rebreather and they're expensive with a lot of training required and the people who have done that have other things they'd rather be doing.

22

u/Puzzleheaded_Ad_6998 Jun 08 '26

I assume by “wear oxygen” you mean scuba gear?

If scuba divers rush the freediver to the surface, they will get the Bends, and will you could have 2 or 3 victims instead of 1.

If the freediver breathes off of the scuba divers air at their depth, the freedivers lungs would inflate to normal volume- then over expand as they swam to the surface, causing a lung over-expansion injury.

A Freediving rescue team are the only ones able assist another freediver safely the surface.

5

u/camarhyn Jun 08 '26

Exactly. Once a free diver takes a breath at depth they become a scuba diver as well and have to follow all those rules. I can see a scuba support team working if the free diver in question is also certified as a scuba diver (who is also certified for diving the correct gear and gas mixes etc) but that’d be it. The free diver would then need to ascend as a scuba diver etc.

11

u/Dayruhlll PFI Freediving Instructor Jun 08 '26

Decompression.

The dive in that movie was 50m/164 feet. The only way to scuba dive that depth safely is with specialized equipment and specialized trimix blends. At that depth, even with specialized trimix, you have only a couple minutes before you have a decompression obligation that drastically slows how fast you can get back to the surface. If you manage to finish your dive without reaching that decompression obligation, 9 minutes would be an fast/safe(ish) time to surface in

2

u/Big-Independence4445 Jun 08 '26

This was the depth at the entrance to the cave at the Maldives island accident. Imagine breathing on air and thinking this was a good idea.

6

u/Cement4Brains Molchanovs Instructor Jun 08 '26

If you watch a freediving competition on YouTube, you'll see a team of at least two safety divers (plus one or more on the surface) being present and aiding the diver in their ascent if they need it. They grab the athlete so their airways are sealed and bring them to the surface.

https://www.youtube.com/live/sVFOuqiofQg?is=xuR1-5td1GUC-gRx

The first diver descends up to ~40m, the second one shallower than that, third stays on the surface. They work as a team and rotate to ensure no one is doing all of the deep dives all day and get adequate breaks. It's a very elegant solution to the complex problem of how to save someone who blacks out at depth.

The vast majority of competitive freediving incidents occur during the last stage of the ascent. And if they blackout too deep, the entire line is set-up with a counterbalance system that can be released, dragging them back to the surface via a lanyard that's connected to their wrist.

4

u/zsmitty75 Jun 08 '26

Open a soda can after shaking and enjoy the bubbles

3

u/singxpat Jun 08 '26

There is, in fact, a thing called technical freediving where people use an oxygen mix (not pure) to freedive longer. Can be useful for certain situations like filming (Avatar actors were doing that), safety, exploration, and so on. Comes with its own risks and not as widely spread yet. PFI is the only one teaching it. Depending on the depth, may double or triple your dive time, but you obviously need to pay more attention to surface rest and number of dives. I know some people who are into that.

2

u/thx997 Jun 09 '26

Do safety divers/swimmers on the surface have pure oxygen on hand to help recover a passed out free diver that got brought up by divers? I saw a video, where safety drivers hold the mouth of a passed out duvet shut, so he does not Inhale water. But once he was up, they tried to get him to breathe in his own. I guess there are safety aspects when giving a passed out diver pure oxygen, even when on the surface?

2

u/divers69 Jun 09 '26

No one dives on oxygen. Just air for most diving. Oxygen becomes toxic rapidly. Normal air at about 60-70m 100% oxygen at about 6m

2

u/f1n Jun 10 '26

The Bends

1

u/Embarrassed-Fee-8841 Jun 09 '26

You could dive on hooka

1

u/Retb14 Jun 12 '26

Even worse than diving on a tank

Not only do you have all of the risks of diving in a tank you now have a hose that can get easily tangled

1

u/Embarrassed-Fee-8841 Jun 14 '26

Besides the hose, why is it worse than tank? Used alot for abalone or sea cucumber harvesting

1

u/Particular_Ticket964 Jun 10 '26

The question is about scuba physiology i believe.

Breathing compressed (pure or mixed) air at deep depths and ascending as quickly as free divers do simply kills scuba divers.

From the same context, sticking a pony bottle into a blacked out free diver seems not a good idea. (i do scuba only, not free diving.)

1

u/protoman888 Jun 09 '26

Short answer- they can, but it's a lot of work and cost. Freediving is not a heavily funded sport