Complacency kills - It's not just an empty threat!

[doctormike]

My insistence on culture is due to my experience that risky behavior is generally not called upon and probably most of the time not even noticed, whether by the potential victim or those who surround them. That, more than anything else, breeds complacency. ...

I am just asking: what makes our lapse of judgment possible?

Exactly - I think that you have it right, to focus on culture. It seems like there are two modes of error, normalization of deviance and temporary suspension of what we know to be good practices.

Normalization of deviance is the mode you described above. Poor practices become so commonplace, and performed by so many experienced leaders in the field, that eventually what is considered to be a safe practice is recalibrated. You do something wrong and get away with it often enough, it ceases to be wrong. You do enough dives without a checklist or a pre-breathe, and eventually skipping those things becomes the new standard. Right up until the point of tragedy...

The other mode is when you normally do the right thing but for some reason you don't on this one day. That sounds like what happened to the OP, who normally does the pre-flight checklist, including the pre-breathe. But not on the day of the accident.

Humans are fallible, and there are so many things that can cause an error. I was an UW photographer long before I got into rebreather diving. I had an old Ikelite housing for my DSLR, which relied on a loose O-ring being trapped between the case and the dome port. I always made sure that the O-ring was in good position. And then one day I had a big fight with my wife right before a dive, and then I flooded my rig. No O-ring. Go figure.

That's the point of a checklist. It's one more thing to help us keep doing what we know is right, even when we are angry or tired or sick or distracted by a new toy.

 

[Basking Ridge Diver]

There is a book called "Deep Survival Who Lives, Who Dies and Why" - Laurence Gonzales. Anyway an excerpt from the book - he talks about the practice of Zen teaches that it is impossible to add anything more to a cup that is already full. If you pour in more tea, it simply spills over and is wasted. The same is true of the mind. A closed attitude, and attitude that says, "I already know," may cause you to miss important information. Zen teaches openness. Survival instructors refer to that quality of openness as "humility".

He talks about the brain having a limited amount of "working storage" which is the tea cup. If something or someone interrupts that working storage then some of that working storage is going to get pushed out for new information ("the disruption")... You need the humility or discipline to go back and start all over again... Or you risk missing something that you might normally - uninterrupted - catch...

The book is not about scuba diving but it is a good read and a good reminder of what happens and why you need to be cool under pressure...

 

[cathal]

I recently had a very near death experience at the start of a dive in Truk. I know it sounds dramatic but it is absolutely serious.

The dive was on the San Francisco Maru. This was one of the wrecks I really badly wanted to see during the trip which means I guess I've got to schedule a return visit to do the dive again. I was in the second group jumping in the water and was on a CCR. The short version of the incident is that I jumped in the water and was preparing to dive. I took a breath and felt dizzy. I stopped and took another breath and thought to myself "I should get back on the boat!" The next thing I remember is waking up on the dive deck with people pounding on me and trying to jam a regulator in my mouth. I was able to get up and get inside to the AC, they put me on oxygen and brought me to ER where I spent a few hours sucking down oxygen, taking in an IV, and being poked, prodded and tested. Once I was safe to be released, I went to a hotel by the airport and rested until it was time to go home.

Here's the timeline as given to me by one pf the divers on the boat directly involved in the rescue:

850 entry
855 non responsive at lift, jaw locked
903 on deck non responsive weak pulse, bowels released
905 blue coloration and limp still, forcing oxygen with jaw forced open
908 white sputum no blood, dark blue, tiny pupils, turned in side, pushing stomach and chest to balance forced oxygen intake
910 signs of breathing, jaw releasing
920 responsive and irritable, small amount of phlegm
935 refusing oxygen, moved to air conditioned room, bluish coloring
1000 tired with slightly tight sternum, laying down, rotated again to side, able to breath on demand oxygen
1010 light sensitivity and nausea without vomiting
1030 arrival at hospital, transported on oxygen from boat, demand regulator. IV installed with .9% sodium chloride. Low oxygen notated by finger monitor of 89, increased to 96 and removed monitor
1100 ekg completed and xray of chest he was able to stand with assistance.
1105 complaining of cold and stiff on small gurneys. Wrapped in sheet and towel, resting.
1110 drowsy with pink hue returning to face.
1210 stood up and walked 10 steps to bathroom on own, light clear urine.
1220 complaining of mild headache, onset/increase about 10 min ago. Does not desire anything to eat at this time. Confirmed desire to stay away from all narcotics. Turned on side, drifting off to light sleep.
1400 checked into L5, resting in cool room, drank 1/3 bottle of water. Fruit smoothie, water and diet coke in fridge. Urinated almost clear.

Now that all that is up there, here's the nuts & bolts of what happened & why.

I had sent my unit in for annual service before the trip. Oxygen sensors were replaced, all the o-rings were replaced, first stages were serviced, all the hoses were replaced and the latest upgrade to the unit was installed. I got the unit back, but did not get an opportunity to dive the unit before packing it up for the trip. This was my first error. When we got onboard, I put the unit together and did all the necessary items on the checklist. The next morning, before the first dive, my computer was not connecting to the unit. I disconnected the cable, wiped the connectors and reconnected everything, and it worked. This problem reoccurred a number of times during the week. Error number 2. One of the first rules I was taught is very simple - never start a dive with a known issue. I did it anyway, kept an eye on it and for the first 5 days everything was OK. Then came the morning of the dive. The first group splashed followed shortly by my dive buddy. I grabbed my camera and put my Paralenz on the mask strap, and got into my gear. My buddy was in the water waiting for me, and I let myself start to rush. This is the next error, and where things really started to go bad fast. I opened the oxygen & diluent valves, verified my bailout was on, and checked my inflator. I put my loop in my mouth and went to the dive deck, and jumped in the water. The final error was that I did not verify my solenoid was firing. In my rush to get in the water, I breathed the PO2 in my loop down to a level that would not support life. The computer was not connecting (again) to the unit, and the solenoid would not fire. In my rush to get in the water, I did not manually add O2 and I did not notice my dropping PO2.
The rest is history. My buddy saw me and called for help, and dragged me to the diver lift. The other divers on the boat pried my jaws open and forced as much oxygen as they could into my system, until I started breathing again. They got me out of my gear and got me to the ER as fast as possible.

This specific incident took place on a CCR, but even open circuit divers need to be diligent with their dive planning and pre-dive preparations. There are plenty of things that can go wrong with your equipment, both diving CCR and OC. Allowing yourself to skip vital pre-dive checks can lead to fatal consequences.

The only things that saved me from becoming a line on a crappy spreadsheet were the fact that I inflated my wing more than normal (since I had extra bailout) and the actions of the other divers on the boat. Had I been negative when I went in the water or had my buddy and the other divers onboard not been attentive, I would not have made it home alive.

When I got back to the US, I sent the unit back in to the factory. The computer was replaced and the unit fully checked out. Once everything was verified to be operational, I took it out on a few dives. Obviously my pre-dive checklist was very thorough, I verified my solenoid was operating before even standing up to jump, and all systems were verified to be working properly.

In hindsight, I learned a great deal from this incident. My future pre-dive planning and checklists will be done with this incident in mind, and if it takes me 5 more minutes to get in the water, so be it. I've always been good about replacing cells, and before this I was normally much better about my pre-dive. The bottom line is that complacency can and will kill you if given the opportunity, and there may be little to no warning that it is coming. The difference between life & death is a single breath, and I when I took the last breath and thought "I should get back on the boat!" it never crossed my mind to just drop my bailout valve from my mouth and take a breath of air. It seems so obvious now, but once I took that dizzying breath, my mind was unable to think of the obvious - there was no clear thought at all. All the training, all the skills practice, all the thoughts that "It will never happen to me" meant nothing, my brain simply did not tell me to do anything. There is very little time to react when things get to that point.

Don't let it happen to you.

Please note that I have left out the specific unit and the names of the others involved. The name of the unit is of absolutely no value here, since the human failures were of much greater significance, it could have been any unit and the scenario would not have changed. The other divers involved have my eternal gratitude, I can never repay them for saving me.

Thanks a million for sharing such a traumatic incident and for your honesty in your analysis. Very helpful.

Cathal

 

[Neilwood]

Very scary story but so glad it had a non tragic outcome.

I have to say I am not a rebreather "pilot" but if I were to ever get one, I think I would, especially after reading @hroark2112 's experience, get a preflight list printed on a slate with tick boxes beside each step and have that attached to the rebreather. Even then, if you allow yourself to get in the mindset of rushing (it doesn't need a buddy pushing you to feel rushed) you can make mistakes.

Even diving OC if I haven't been in the water for a while I need to be extra careful to make sure of my kitting up procedures (to the point of even thinking about a wrist slate with them on it).

 

[Shasta_man]

If it was a topside device we could put a touchscreen with checkboxes to touch and select before the thing turns on. Yes, you could still just do it without thinking but something has to force people to go through the list otherwise it can defeated by the complacency that runs through all these accidents.

 

[doctormike]

If it was a topside device we could put a touchscreen with checkboxes to touch and select before the thing turns on. Yes, you could still just do it without thinking but something has to force people to go through the list otherwise it can defeated by the complacency that runs through all these accidents.

Some rebreathers do have electronic checklists. I have heard that some divers with these just memorize the number of button pushes it takes to run through the list.

 

[rjack321]

Some rebreathers do have electronic checklists. I have heard that some divers with these just memorize the number of button pushes it takes to run through the list.

Anytime you are "on autopilot" like this you are setting yourself up for disaster.

I recently learned an occasional buddy of mine has "never" done a prebreathe. Their instructor is well known and regarded in NFL too. I am struggling to grasp how this perspective formed - and if I even want to dive with them ever again.

 

[hroark2112]

I think there’s a difference between the old school “5 minutes prebreathe to activate the scrubber” that some used to preach and breathing the unit to ensure the oxygen is working (whether a solenoid or leaky valve) and the electronics are reading properly. It’s not necessary to breathe the unit for a period of time to make the scrubber work, if that were the case we’d all have been dead of hypercapnia on the prebreathe!!

I’m not sure which instructor you’re talking about, but he or she may just be saying they don’t do the old school 5 minute prebreathe, I’d be willing to bet they do breathe the unit before they splash to make sure things are working properly.

 

[rjack321]

I’m not sure which instructor you’re talking about, but he or she may just be saying they don’t do the old school 5 minute prebreathe, I’d be willing to bet they do breathe the unit before they splash to make sure things are working properly.

Only in retrospect did I realize that I've never seen this buddy do a prebreathe. So I am thinking their "I have never done a prebreathe" is accurate

 

[hroark2112]

Have them read this thread before they have to write their own (or worse).