Searching for opinions about Rescuing a diver and decompression stop

[ucfdiver]

@ucfdiver
If there are really 5min of delay before DCS occur, I wouldn't mind blowing my deco to transport the victim to the surface If I can do it immediately after.
But is there such delay ?
I've heard of inner ear decompression sickness which could be provoked even at depth (isobaric counter diffusion when doing a gas switch for example).
It's pretty far away from our subject, but does anyone have any data on the 5 min delay ?

And now the post is in the technical forum what about rescuing from a very deep mixed gas diving, where, the time to get to the surface could go well beyond 5 min (and I doesn't speak about deco yet ^^).

Well, commercial divers seem to have a 5 minute window before getting into chambers, so it's my understanding that the 5min window is generally accepted.

This really all comes down to an inconvenient truth-- if you're doing deco dives long enough where blowing off deco is deadly, you need a support team in the water, and if you're doing deco dives where it's going to cause a severe DCS hit risking neurological injury even if chamber treatment is given within a reasonable amount of time, you need at least someone on the surface there to call 911 if you have to ditch a buddy.

 

[briaeros007]

well dont dive with me then cus you're going up. I'm not letting anyone drown if I can help it. I couldn't live with myself.

As long as I don't need rescuing while having some heavy deco, it must be fine, isn't it ?

As a diver, I doesn't want that someone take too much risk to "save me".
I know the risk when I'm going underwater, and I doesn't want to be a burden on the rescuer.

While you couldn't live with yourself if you let a buddy in need underwater, if I'm a victim, i couldn't live with myself too if the rescuer became incapacitated when he try to save me.


And as I said, this was "from my couch". It's possible that underwater i would take much more risk than a rationnal decision would have allowed me.

 

[LiteHedded]

then there are other fun factors to consider. like whether to waste time jamming a reg in a toxing diver's mouth.or to bother keeping the airway open, which would likely drown them as opposed to a lung over expansion. one survivable, one not.
these things are all very bad scenarios. also, if you've ever tried bringing someone up in this fashion it's not easy and takes time

 

[TSandM]

I think the "five minutes until you are in trouble" depends on the nitrogen load AND the rate of ascent. I certainly would not count on it as a safety factor if I had a heavy deco obligation.

In answer to the 4 person question . . . it is best to divide such a group into two groups of two from the outset of the dive. The four may dive together, but as two buddy teams. If someone has to go up, their designated buddy is the person who accompanies them.

If you have a major medical emergency and nobody has much deco, the other two may CHOOSE to surface to expedite the evacuation of the ill diver. This is going to depend somewhat on where you are, and what the evacuation procedure IS. (If it's a helicopter pickup, there's really no need for the other two to blow off their deco, but if the only way to get the diver to help is to run for shore, they may choose to do it.)

You can sit and muddle your head with scenarios (from your couch, as you put it) until the cows come home. The fact is that major decompression obligations create a whole host of additional considerations. I ran a boat for a pair of friends doing a 200 foot dive once, a couple of years ago. I wouldn't do it again, at least the way we did it. We had no additional gas on board, I had no gear, and there was no one else on the boat. In other words, the divers were on their own in the water, and I think at 200 feet for 20 minutes, that's exceeded my threshold for thinking that more support is needed.

Things like this are why technical diving is so much about planning.

If you don't think such issues can occur, you should read the account of the double fatality in Northern California this summer. Two technical divers, doing a planned dive with significant deco, encountered a recreational diver at 140 feet who then ran out of gas. One of the tech divers shared air with him and got him up to the 70 foot stop, but made the decision that the diver was not sufficiently in control to execute a prolonged decompression schedule with his rescuer. The gas donor then took the OOG diver to the surface, watched him exit the water, and returned to do omitted decompression.

The OOG diver subsequently died, and the tech buddy who was left at the 70 foot stop was later found on the bottom, dead. All I could think, when I read the story, was that the gas donor was faced with an impossible decision that I never want to have to make.

 

[PfcAJ]

Then comes that fuzzy line of how one defines a 'major' decompression obligation. 30mins? An hour? Where's that line?

This is why I spend my time working on never having to encounter any of these scenariors. An ounce of prevention is worth a pound of the cure.

 

[DevonDiver]

I think many of the OP's questions would be unnecessary if they undertook some specific deco/technical training, rather than a hot-potch 'light deco for recreational divers' certification. If such fundamental questions are still unanswered following the training, then the training is obviously not sufficient for the task intended.

Putting aside the vagaries of specific rescue techniques (re-inserting regs etc), what I was taught (my training didn't force me to seek answers online) was that:

1. You don't risk making yourself a second victim when conducting a rescue, as that only stretches rescue resources and can jeopardise the survival of the original victim. IMHO, ethically,if you do opt to take such risks to conduct a rescue, you should also be committed to forgoing later treatments should necessary resources be insufficient and cause conflict between your needs and the original victims.

2. You don't conduct in-water recompression, unless such treatments are supported by the full and extensive planning and logistical support needed for safe outcome. You shouldn't hypothesis about in-water recompression treatment, or consider its use, unless you are fully educated about what is involved and why.

3. You should dive in full awareness of missed/omitted deco procedures and apply them intelligently if required.

4. Opting to deliberately miss/omit deco to rescue a casualty, with the intention of rectifying the deco immediately afterwards, is very situationally dependent. It is not a safe option - so better options should be planned/prepared for in advance.

5. 'Light' deco is not a misnomer for 'ok to skip deco'. If you opt to skip deco, you should only do on the basis that you stand a high chance of getting DCI.

6. There are many options that can be instituted to ensure that you have adequate support during a deco dive - which will cater for this scenario. The use of surface and in-water support, along with corresponding procedures, eliminates the need for a diver with deco obligations to take excessive personal risks. If your 'toolbox' doesn't include the knowledge needed to implement such options, then your training is lacking for the dives you are doing.

 

[briaeros007]

I think many of the OP's questions would be unnecessary if they undertook some specific deco/technical training, rather than a hot-potch 'light deco for recreational divers' certification. If such fundamental questions are still unanswered following the training, then the training is obviously not sufficient for the task intended.
Putting aside the vagaries of specific rescue techniques (re-inserting regs etc), what I was taught (my training didn't force me to seek answers online) was that:

Actually, I already have my "light deco for recreational diver" certification, and initially the post was in "basic scuba question".

I'm training for something that would be something like "depth and autonomy for recreational diver".
In addition, This such fundamental question have got different answer as I've already indicate.
Each organization, and each diver have a slightly (or not so slightly) answer.

I've got multiples answer from multiples person (online, my instructors, other instructor from the same organization, other instructor from other organization, books, ...).
Personnally I prefer to see all sides of a coin (different thought, different training, differents experiences) to make my choices, and to not rely only on my training with only a few instructors (which are humans, as all of us).


In this way, It's easier to me to comprehend all the involved risk, the possibility of such procedures, their limits.

1. You don't risk making yourself a second victim when conducting a rescue, as that only stretches rescue resources and can jeopardise the survival of the original victim. IMHO, ethically,if you do opt to take such risks to conduct a rescue, you should also be committed to forgoing later treatments should necessary resources be insufficient and cause conflict between your needs and the original victims.

2. You don't conduct in-water recompression, unless such treatments are supported by the full and extensive planning and logistical support needed for safe outcome. You shouldn't hypothesis about in-water recompression treatment, or consider its use, unless you are fully educated about what is involved and why.

3. You should dive in full awareness of missed/omitted deco procedures and apply them intelligently if required.

4. Opting to deliberately miss/omit deco to rescue a casualty, with the intention of rectifying the deco immediately afterwards, is very situationally dependent. It is not a safe option - so better options should be planned/prepared for in advance.

5. 'Light' deco is not a misnomer for 'ok to skip deco'. If you opt to skip deco, you should only do on the basis that you stand a high chance of getting DCI.

6. There are many options that can be instituted to ensure that you have adequate support during a deco dive - which will cater for this scenario. The use of surface and in-water support, along with corresponding procedures, eliminates the need for a diver with deco obligations to take excessive personal risks. If your 'toolbox' doesn't include the knowledge needed to implement such options, then your training is lacking for the dives you are doing.

I agree with all the points, but to some extends :
5- i don't see light deco as "ok to skip" but as "little risk to get a DCS, and really little risk to get a DCS wich couldn't be treated totally".
(and I will add that decos doesn't prevent totally the DCS, but diminish greatly the risk to have one, and the gravity of it).
So If on the other side, I see my best friend dying, I wouldn't have too much thought getting some "little" dcs to save him (and pray that no DCS will be declared in the brain or other really sensitive area).

6- Sometimes training and/or planification are not sufficient (because we have gone beyond our limits, our training, murphy law, ...).
We can look away, but theses things could happen, and once it's enough.

 

[MarkHerm]

If you don't think such issues can occur, you should read the account of the double fatality in Northern California this summer. Two technical divers, doing a planned dive with significant deco, encountered a recreational diver at 140 feet who then ran out of gas. One of the tech divers shared air with him and got him up to the 70 foot stop, but made the decision that the diver was not sufficiently in control to execute a prolonged decompression schedule with his rescuer. The gas donor then took the OOG diver to the surface, watched him exit the water, and returned to do omitted decompression.

The OOG diver subsequently died, and the tech buddy who was left at the 70 foot stop was later found on the bottom, dead. All I could think, when I read the story, was that the gas donor was faced with an impossible decision that I never want to have to make.

wow.... what a horrible situation with a horrible outcome, unfortunately.

 

[DevonDiver]

Actually, I already have my "light deco for recreational diver" certification, and initially the post was in "basic scuba question".

Which is the point I made. If you did more adequate training for deco....and NOT a "light deco for recreational diving" course, then you probably wouldn't need to ask these sorts of questions in the first place.

If the lightbulb clicks on, then the little voice inside will say.."ah... so there's more specific training I should have done, that would have told me more about this issue...and many other issues... that my current training neglected to provide me with before sanctioning me to dive under these conditions!?!?"

Each organization, and each diver have a slightly (or not so slightly) answer.

This is true. Most organizations approach deco diving from a technical perspective, which develops a breadth of specific skills, procedures and knowledge to answer the obvious questions posed when operating with a deco obligation. A couple of organisations don't - preferring to maintain antiquated training standards that were rendered insufficient when technical training became increasingly available, accessible and affordable.

Flicking through some antique US Navy tables and chuffing a pre-dive Gauloise is no longer a widely supported method of pre-dive planning for a 60m air dive on a single cylinder.

 

[ajduplessis]

I am generalising here but if you don’t see the incident happen and very close by, things are not good for the victim. Also, once the breathing valve is out of the mouth chances of surviving are less that 3% if not lower. In a deco situation with a rescue attempt TIME is the enemy. You have to make some hard choices. Do you stay and keep the victim in the water, or do you surface and face the music. You might have to blow your stops, unless there are other none deco divers to help get the victim out of the water.

Hope I never have to make calls like that.