Well, what could go wrong?

[diver 85]

Short story:

Both in chronic 'poor' general health due to each being a brittle diabetic & uncontrollable HTN---Each, remarkably & almost simultaneously(remember they were a match made in----well somewhere) stroke out & perish topside after a 'wonderful' dive.....

Now, saying all this, it was 'their' time to go---whether 100 foot below or sitting @ Burger Doodle eating their usual daily 3 double cheese greasy burgers with extra mayo & extra large sized fries....When the bell tolls, you're a goner, no matter who/what's around....

 

[TSandM]

No, actually, there's no hidden meaning in anything. When I said they planned their maximum bottom time, I meant they set a maximum parameter for how long they would consider being at each depth. It could have been based on gas, or it could have been based on NDLs, whichever was governing that dive.

Guba, I'd love to hear your contributions on things that can go disastrously wrong despite good planning and good execution. That's the kind of thing that would make this thread a real educational experience for someone reading it.

Thanks to the folks who mentioned falling on the boat ladder. That's another good one.

 

[redacted]

It is not that good planning eliminates all problems. Bad planning may create opportunities for problems that could have been controlled, but good planning only serves to reduce the likelihood of problems or their impacts when they occur.

 

[Crush]

According to DAN's Annual Diving Report, 2007 Edition (based on 2005 data), the following is true of dive injuries (as opposed to fatalities):

1. 65% of injuries are to male divers, so statistically it is likely Bob who was injured;
2. The most likely diagnoses (as % of reported) in case of injury, and mean max-depth of the dive on which the injury is reported to have occurred are: barotrauma (28%, 51 fws), DCS (23%, 92 fws), trauma (8%, 58 fws), and envenomation (7%, 43 fsw) with the remainder of injuries being ascribed to non-diving related (28%, 58 fws) and "other" (16%, 58 fsw). Given their dive profile, the statistically most likely injury is DCS. The maximum and minimum times to the onset of DCS symptoms are 264 and zero hours, respectively, with a mean of 9.2 hours. Bob can therefore have DCS but not be manifesting any symptoms. The most commonly reported DCS symptoms were "pain (any)" and paresthesia (i.e., subjective cutaneous sensations such as cold, warmth, tingling, pressure, etc., that are experienced spontaneously in the absence of stimulation), with respective mean times to onset of 11 and 10 hours, respectively.

Bob may have taken an undeserved hit - it is rare, but it does happen.

 

[Blackwood]

Your outline says they stay together until they get on the boat. Do they actually get on the boat?

A major concern I face on/after a lot of dives is boat traffic. It seems that a great many pleasure boaters don't know what a dive flag means, and when someone gets on the horn to yell them away they come even closer to figure out what's going on.

And then there are things like the ship below, a good number of which may pass within a mile or less of us on a given dive day in the san pedro/long beach bay.

I may hold this concern more fervently than others being that I knew someone (non-diver) who was struck and killed by a jetski, but anyone who dives in areas of boat traffic should recognize and attempt to plan for such a hazard.

 

[gcbryan]

Gray, that fatality at Alki might well have been avoided if the victim had taken the step of inflating his BC before getting near the water, which is something I stress to student divers when I am doing the DM thing.

That's true and that's why I said there were other explanations as well. However, it's still a pretty benign situation usually. One could put air in the BC when stumbling over logs and slippery rocks and then deflate in preparation to go under and simply not have a reg in the mouth yet and the same thing could happen.

I'm just saying it's a situation that usually would not result in serious injury or death at a location like that so it's the closest thing I can recall off the top of my head to someone doing everything mostly right.

In hindsight it's almost always possible to find the mistake but I'm pretty careful but I can't say that I would never be in his particular situation and I think most of us could at one time or another at a site like that.

OK, to add to the Bob and Karen scenario...they plan and dive their dive but while underwater someone else didn't and upset their carefully laid plans. They chose to help out and were injuried themselves.

 

[Herk_Man]

I think what you're getting at here is that they planned to go to the maximum bottom time. Any time you don't leave yourself a buffer on your limits, you risk the introduction of unplanned circumstances causing you to exceed those limits and put your lives in jeopardy.

So the dive plan was faulty in that they didn't allow some cushion in the timing of the dive to deal with a variety of scenarios that would cause an OOA or DCS situation.

 

[Herk_Man]

That's true and that's why I said there were other explanations as well. However, it's still a pretty benign situation usually. One could put air in the BC when stumbling over logs and slippery rocks and then deflate in preparation to go under and simply not have a reg in the mouth yet and the same thing could happen.

I had to laugh when I read this. The closest I ever came to being a statistic while diving was after a long surface float waiting for the rest of the divers on a group dive to get in the water. We all signalled the descent. Nobody, including yours truly, noticed that I was still breathing off of my snorkel instead of replacing it with a regulator. Glug glug!

Another reason my snorkel spends the majority of my dives at the bottom of my gear bag.


:bonk:

 

[Cave Diver]

I'm getting jaded, reading accident and incident reports.

Assume Bob and Karen go to do a dive. They look at the planned depth of 100 fsw, with a multilevel profile, coming up a wall. They compare that profile to their own gas consumption on their HP100 tanks, and conclude that this is a dive they can do. They make a plan for maximum bottom time at depth, and sketch out a desired profile. They gear up on the boat and do a careful head-to-toe equipment check, including breathing both regulators and watching their gauges as they do so. They review the plan and the gas supply each of them has.

They jump in the water and descend together, keeping a watchful eye on the group guide. They execute the dive, paying close attention to the planned profile and comparing it to the dive as it unfolds. They watch their pressure, mindful of the rock bottom reserves they discussed on the boat.

They call the dive at the agreed parameter (gas or time) and ascend together, arriving at the surface as a pair. They remain together until they reboard.

Okay -- here's the challenge. Tell me what could happen (other than being eaten by a shark) that could cause a serious accident or fatality, given that the dive is executed as described.

Ok Lynne, I'll play. But first I'm going to take exception to the part above in bold. If it's "executed as described" then nothing happened. If you want to play "what if" I'm going to change this as follows:

They jump in the water and descend together, keeping a watchful eye on the group guide. They execute the dive, paying close attention to the planned profile and comparing it to the dive as it unfolds. They watch their pressure, mindful of the rock bottom reserves they discussed on the boat.

They plan to call the dive at the agreed parameter (gas or time) and ascend together, arriving at the surface as a pair. They plan to remain together until they reboard.

You also state nothing about their training level, experience or the rest of the group, so I'm going to take some creative liberties and throw the following ideas out there:

• Wall dive, they experience a down welling they aren't prepared for. It takes them beyond their planned depth, causing narcosis, deco, or using excessive amounts of gas.
• Another member of the group is having an issue. They are the only one who sees it, stop to help and the other diver panics, bolts for the surface and rips off one of their masks, regs, etc. in the process.
• Current switches direction during the dive. It's not a screaming current, but it's significant enough to impact gas reserves.
• Going through a coral cave swim through on the wall and they inadvertently get too close and:
  • Gear gets snagged on a protrusion causing a panic, or ripping reg out of mouth and it's hard to recover.
  • Receive a nasty cut from coral
  • Contact with fire coral or bristle worm
  • Last diver feels claustrophobic, doesnt enter, attempts to find the group on the other side and becomes separated.
• Group runs into a pack of jelly fish
• Diving into a current and mouthpiece comes loose/rips off regulator causing them to inhale a breath of water and choke.
• One of them starts to feel ill, perhaps something from breakfast didnt agree with them and they have painful, debilitating cramps.
• This is their 4th day of multilevel diving. One of them had been sick the night before with vomiting or diarrhea. Today they felt fine, but the combination of mutli day diving, dehydration, poor rest, or meds causes them to have DCI symptoms on surfacing.

While none of the things I listed above are likely to be the direct cause of a fatality, there is seldom one single issue that does anyway. Rather it's a chain of events, that is set in motion by a single issue. When that issue remains unresolved, things can build to a point of no return.

Before everyone starts on the "what are the odds of any of those happening" track, almost everyone of those examples came from events that I have first hand knowledge of. They may not have happened to me, but I know that they did in fact, occur.

 

[Blue Sparkle]

Your description has them re-boarding the boat alive. Complete newb nobody here but that makes it hard to tell what you're asking. In a strict logical sense only health issues on the surface or non-diving boat/weather trouble could be an issue at that point. I think maybe we are supposed to imagine things that could happen to interrupt this story before their return to the boat?

I got stuck there too. I'd like to play, but I'm not sure if you mean we are supposed to imagine things that happen after the end of the original "story," (i.e. they are both on the surface and the dive went fine, as planned), or if we are supposed to break into the middle and insert new "facts."

B.