What should I know about your gear?

[Bubbletrubble]

I would consider sending the diver to the surface buoyant if I knew how long they'd been missing and it was excessive, or if I had a significant decompression obligation. On a recreational dive, I'd do a rescue ascent as I was trained.

That's a sensible approach. I'd be interested in hearing what you deem to be "excessive" (10 min, 30 min, 45 min, 1 hr, 1.5 hrs) in terms of how long the diver has been missing.

I didn't want people to read the thread and think: "OK. If I'm searching for a missing diver and I find him not breathing and unconscious underwater, then I should shoot him to the surface so that he can get help there. Case closed." That's not the way it's taught in Rescue class...and for good reason.

 

[rstofer]

If the diver had been down for a LONG time, would anyone consider just marking the scene with an SMB? There is the remote possibility that this is a crime scene. Where's the diver's buddy? On the powerboat sipping champagne with the new widow?

Richard

 

[Bubbletrubble]

If the diver had been down for a LONG time, would anyone consider just marking the scene with an SMB? There is the remote possibility that this is a crime scene. Where's the diver's buddy? On the powerboat sipping champagne with the new widow?

Once the operation is a recovery, then I would think that marking the scene with a SMB is a valid option. This becomes an even better idea if you can't very easily bring up the body single-handedly in a controlled way (due to entanglements/entrapment).

You bring up an interesting point about the possibility of it being a crime scene.

 

[TSandM]

I would say that, if someone is overdue more than 15 or 20 minutes beyond where their gas supply would be expected to last, that's excessive.

 

[Bubbletrubble]

I would say that, if someone is overdue more than 15 or 20 minutes beyond where their gas supply would be expected to last, that's excessive.

That sounds reasonable.

Out of curiosity, let's do some back-of-the-envelope calculations to see how much "search time" this translates into...
The upper limit of successful rescue time (SRT), defined as how long the missing diver could be underwater and still survive, could be estimated in the following way:
Assuming a RMV of 0.5 cuft/min and an AL80 tank, this would translate to an unstressed "breathing time" of 160 min if the diver were at 1 ata. Decrease the breathing time accordingly if the diver was known to be at a certain depth.
For instance, if the diver were lost at 33 fsw, then the upper limit SRT would be 80 min + 15-20 min (overdue time) = 95 - 100 minutes.
If the diver were lost at 66 fsw, then the upper limit SRT would be roughly 53 min + 15-20 min (overdue time) = 68 - 73 minutes.
If the diver were lost at 99 fsw, then the upper limit SRT would be approx. 40 min + 15-20 min (overdue time) = 55 - 60 minutes.

[N.B.: These calculations only consider gas supply in determining upper limit SRT. The negative effect of decompression stress or any other instigating factors causing the buddy separation incident are excluded. The typical 77.4 cuft capacity of an AL80 was rounded up to 80 cuft to simplify calculations.]

Something tells me that Coast Guard/lifeguard teams probably have performed similar calculations to help inform the transition from rescue to recovery efforts in missing diver scenarios.

Just thinking out loud here...

 

[H2O 70]

@H2O 70: I bold-faced the text that I find questionable. Hooking a dive reel to the non-breathing unconscious diver and shooting him to the surface by inflating his BCD gives you little or no control over the ascent phase of the rescue. It essentially turns the victim into a SMB! If you ascend with the victim, you can control the rate of ascent and keep the victim's neck in a neutral position to mitigate the possibility of pulmonary over-expansion. Also, consider what might happen to the victim if there is an overhead obstruction (boat hull) directly above. Adding a traumatic head injury to whatever else caused the incident is not a good idea. In any rescue scenario, you should assume that the victim can be rescued (if not, what's the point?) and make the best decisions to get him/her to the surface with the safest/most efficient method possible that does not place you in an unacceptable level of danger.

IMHO, shooting the victim by himself to the surface should be an act of last resort.

Did an instructor really teach you this or agree with your synopsis?

We were not taught this technique. We were taught to do a controlled ascent with the victim.

With that said, maybe Ts&M can chime in here along with other medical personal. My instructors had medical backgrounds. Their argument was shooting, yes, just like an SMB, an unconsciousness, non-breathing diver, who you found on bottom w/o a regulator in their mouth was as follows...(a) if their lungs are full of water (wet drowning), well AGE is unlikely and (b) if their lungs are dry (dry drowning) the muscles in the trachea that spasmed shut will basically relax with the loss of consciousnesses or death and air can escape again making AGE unlikely and (c) AGE is treatable, death is not and (d) one victim is better than two.

For each minute of cardiac arrest, and we'll assume that cardiac arrest has occurred in the above scenario, there is a 10% less likely chance of positive recovery. If we're at 100ft, were talking about 1.5 minutes or 15% less chance of a positive recovery. If I can get them to the surface in 20seconds where there is a chance that someone on the boat can respond get them hooked up to an AED, preform CPR and rescue breathing with O2, I'd say their chances of recovery are greater.

To prevent an arguments or misinterpretations I would not do this with a diver I found unconscious, not breathing WITH a regulator in their mouth.

 

[fnfalman]

What should people know about my gear? They should know that my gear is best fit to me.

Seriously.

I choose my gears to fit my style of diving, as should everybody else.

As far as encountering divers in trouble whose gears you're not familiar with, cut it all away and rescue them. A $10,000 CCR means nothing if the diver is dead.

 

[Herk_Man]

Funny,the 1st responder seemed to understand very well.
I also find it helpful to read the OP before replying to a thread.
Besides,I suspect you are just trying to aggravate me because of our last encounter.

Our last encounter? I don't even recognize your name. Whatever it was, I'm over it. You probably should be too. Kudos to the first one to post. I guess me and about 40 others are just ignant. Sorry.

 

[ptyx]

Consensus of our group would be to hook a dive reel to them and if their BC inflated, shoot them to the surface. For all practical purposes they are dead anyway.

I'm not sure what the benefit of that approach is.

It is easy to let go from a standard rescue hold at any point in the ascent - remember, you're using the rescued BC for buoyancy, so he will make his way to the surface in all cases.
On the other hand, once the rescued diver has been transformed in a shooting bag, there is no hope of recovery.

Even if at some point you choose to send the rescued on its way alone to the surface (a reasonable option in case of deco obligations), why not do so as close to the surface as possible?

Compared to shooting from the bottom, it doesn't negatively impact your own deco obligations, gives you more time to assess the rescued condition, doesn't impact the rescued time to the surface too much and seriously limits its risk of AGE.

 

[Bubbletrubble]

We were not taught this technique. We were taught to do a controlled ascent with the victim.

With that said, maybe Ts&M can chime in here along with other medical personal. My instructors had medical backgrounds. Their argument was shooting, yes, just like an SMB, an unconsciousness, non-breathing diver, who you found on bottom w/o a regulator in their mouth was as follows...(a) if their lungs are full of water (wet drowning), well AGE is unlikely and (b) if their lungs are dry (dry drowning) the muscles in the trachea that spasmed shut will basically relax with the loss of consciousnesses or death and air can escape again making AGE unlikely and (c) AGE is treatable, death is not and (d) one victim is better than two.

For each minute of cardiac arrest, and we'll assume that cardiac arrest has occurred in the above scenario, there is a 10% less likely chance of positive recovery. If we're at 100ft, were talking about 1.5 minutes or 15% less chance of a positive recovery. If I can get them to the surface in 20seconds where there is a chance that someone on the boat can respond get them hooked up to an AED, preform CPR and rescue breathing with O2, I'd say their chances of recovery are greater.

To prevent an arguments or misinterpretations I would not do this with a diver I found unconscious, not breathing WITH a regulator in their mouth.

@H20 70: Thanks for your response. The situation being considered is dire, no question. It's an interesting rescue effort to ponder. FWIW, I had similar thoughts to what ptyx articulated.

Could you please elaborate on the reason for making the distinction between finding the diver with the regulator in mouth vs. out of mouth? My guess is that there is a higher probability that: (1) the diver just recently stopped breathing and/or (2) the diver's airway is protected.

I still think that the best course of action when finding a non-breathing, unconscious diver with reg not in mouth would be to do a prompt (60 ft/min) ascent with the victim to the surface. Shooting him to the surface unaccompanied may save about 1 min, but without you at the surface to yell and get the attention of others, it may be another minute before they realize that the victim is now at the surface. Precious time is lost. Unless there's an issue that I'm overlooking, I still think the best course of action is to accompany the victim to the surface.

Personally, I've already decided that I will not burden myself with a deco obligation during a rescue operation simply because it forces me have to make even tougher decisions once the victim is located. If my computer tripped into deco during the ascent, then I'd still choose to accompany the victim to the surface. My Suunto computer uses a conservative algorithm, and I'd be willing to accept the minimal DCS risk.