Analysis of Mia's fatal dive

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Posted by MHK on February 13, 2001 at 16:46:59:

We spend a significant amount of our time on this list debating semantics and arguing over definitions and this isn’t why I’m on this list. With respect to Mia’s fatality we have sadly been presented yet another opportunity to learn from the mistakes of other’s. In the old days (pre-internet) the scuba industry did what it could to minimize the exposure of fatalities in order to prevent people from being scared off. I believe, in contrast to that position, that WE DIVER’S should in fact discuss these incidents for it is the only remaining contribution these divers’s can make and so other’s can in fact learn from the mistakes to prevent it from happening again. Lists such as this one have provided a medium that wasn't available a few short years ago.

I’ll stipulate from the outset, that this is my opinion and this is what I believe we can take away from this most unfortunate accident.

The general facts as we know them are, Mia was a very experienced diver (3000+ dives); she was in a buddy team from the outset, but yet chose to continue the dive when her buddy indicated he was low on air; this was the second dive of the day, Dive 1 @ 100’ and dive 2 @ 85’; she was breathing standard compressed air; she was wreck diving; she surfaced indicating she was OOA but her computer indicated that she needed added deco; and it doesn’t appear that an adequate emergency plan was in place.

It seems to me that there were many things that could have been done differently on this dive and any one, or all, are responsible for the fatality and thus deserve examination.

Repetitive dives of this nature should be done using Nitrox and one could offer up the position that had she been using a 36% on both dives it’s possible she wouldn’t have required the added deco. Furthermore, as I have offered, reliance on a computer in and of itself wasn’t responsible for her death. But let’s assume that she had followed our recommendations and incorporated deep stops into her ascent, most computers’ penalize you for this and in fact add time to your NDL limit. Understanding what tissue group (i.e.; the fast –v- slow group and the resulting effects on the M- values) MAY have rendered the computer induced added deco unnecessary. It’s important to note that planning and not getting yourself into this position in the first place is my choice of preference, but acknowledging that she was were she was is what I’m addressing. She found herself OOA and her computer telling her she needed added deco.

When wreck diving ALWAYS use the rule of thirds. 1/3 of your gas supply for the descent and penetration, 1/3 of your gas supply for the exit and ascent, and 1/3 of your gas supply for EMERGENCY.

Obviously, the team protocol wasn’t followed. This is very common when you have experienced diver’s, diving with familiar people. I’m sure she’ll be fine… Famous last words. We preach quite a bit about pre-dive planning and solving the problems before they occur, because when the shit hits the fan, you have limited options and you rather not hope that the diver is skilled or practiced enough to handle it. Experienced divers all too often get complacent and it would appear complacency played a role in this tragedy.

So what should have been done when she popped up and said to her fellow diver’s * I’m OOA and I have more deco to do*???

Most tech divers observe the following rule:

If you are at the surface for less than 5 minutes and are NOT symptomatic, you should go 2 stops deeper than your last blown stop and double the missed deco stops. It should be self-evident that this shouldn’t be done solo if you have divers on the deck.

If you are symptomatic you should NOT re-enter the water, or if you have been up for over 5 minutes. You should hydrate, get on 02 and evac. ASAP.

Substantial attention has been given to her weighting, and it think this is a very important point… Why did she have so much weight on???? A balanced rig is of tantamount importance. You should strive to be neutrally buoyant with 500 psi in your tank at 15’. You should have balance between ditch able and non-ditch able.

We also highly recommend, for the reasons that seem obvious on this dive, that you run your argon (or whatever drysuit inflation source) from a source other than your primary air supply. This is recommended so that in case you do run OOA, you can still inflate your suit. In my mind it’s seem pretty obvious that absent the ability to inflate the drysuit when she went back down she was unable to stay at 15’ because of the weight and the inability to inflate a drysuit or bc. The equipment is reported to have been defective in that she couldn’t ditch. But had she had the argon bottle (i.e.; a 6 or 13 CuFt. Pony bottle) it’s possible that she still could have ascended.

We have beaten the solo issue to death, but it can’t be underscored enough in the instant case that Mia would be alive today if she weren’t alone when she went back down. Her problems, while grave, were not unsolvable when she popped up. I have said on many occasions that when the shit hits the fan, it happens quickly and there is limited time to react. The amount of time that you can hold your breath is what you have to figure out the problem and solve it. Once panic sets in, the window closes fast. A buddy, of course, is a fresh set of eyes, a fresh set of hands, an alternative air source, and a calm head.

Anyway, I’ve tried to leave the DIR propaganda out of this post because it’s clear that’s an emotional issue and I’d prefer those that want to understand what went wrong can have the opportunity to do so absent the requisite DIR flame war.

Most accidents are solved before you get in the water, and my hope is that after reviewing these facts some will take that line of thought with them to the next dive they do.


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