Two fatalities in Monterey

[MXGratefulDiver]

Lastly, I find the unqualified blanket-suggestion to ditch weight in ANY emergency troublesome. However, the discussion about 'When to ditch' and 'When NOT to ditch' warrants another thread.

... as do I. I'm generally in agreement with Mr. Kurtis when it comes to diving philosophy and practice ... but this is one area where I fundamentally disagree ... particularly for the cold water diver.

Ditching weights should be one of several options to consider as an appropriate response to an emergency, and if done, the decision to do it underwater or on the surface should depend on the circumstances.

... Bob (Grateful Diver)

 

[Ben_ca]

In my few trips to dive in Calf waters, it's seemed that boats there are generally quite different than Florida Keys boats - almost liveaboards. Comparing diving between the two locations is obtuse I think. Calf diving is expected to be more challenging so you prepare for it. How well this group prepared I wouldn't know, but that's the general approach.

Don's blanket statement about California boats only applies to the SoCal area channel island fleet that do actually go out on multi day trips.

The boat involved is a not as large as those (42ft long 16 ft wide) versus the Vision (88 X 26) or Conception (79 X 25).

 

[DandyDon]

Don's blanket statement about California boats only applies to the SoCal area channel island fleet that do actually go out on multi day trips.

The boat involved is a not as large as those (42ft long 16 ft wide) versus the Vision (88 X 26) or Conception (79 X 25).

I was referencing my few trips to dive in Calf waters as compared to Florida Keys boats. Two of the three I have been on in Calf were day boats but larger with galleys which I've never seen on F.Keys boats. I'm sure that dimensions vary greatly, but the general differences are still evident. As someone else suggested, if they waited for F.Keys conditions to go out in Calf - it wouldn't happen much.

Now, I have not dived in the northern Calf waters so offer other corrections if you wish.

 

[TSandM]

Peter and I spent some time last night, trying to construct a scenario where the divers would stay together but both die. One of the things we considered was vertigo and disorientation in midwater, and divers who couldn't keep it together to be sure they were always going UP. Dropping weights in this instance, although a last option, would at least solve the "which way is up?" problem.

 

[Lobzilla]

Peter and I spent some time last night, trying to construct a scenario where the divers would stay together but both die. One of the things we considered was vertigo and disorientation in midwater, and divers who couldn't keep it together to be sure they were always going UP. Dropping weights in this instance, although a last option, would at least solve the "which way is up?" problem.

Once in open water "Follow the bubbles". Learned that in the dunk tank where egress from a sinking airplane/helicopter (or car for that matter) is practiced - without scuba gear for the trainees.

Granted, remembering that air goes up in water may be impossible for someone who is in total panic; but why would two divers experience the same degree of vertigo (or other problem) at the same time and not one of them come up with at least an attempt of a solution?

The other thing is that people who panic inhale deeper and will inevitable go up from neutral. Once they go up in the water column, they will keep going faster and faster unless they vent/dump gas. For example, the hardest part of an unconscious diver rescue is to control and eventually stop the ascent once you got it going.

The statement above assumes that we were neutral at some point. If we descend (while negatively buoyant) and black-out, we will be found at the bottom.

 

[Jax]

[ speculation ]

Two inexperienced young men, diving in a totally new-to-them environment . . . perhaps it was as simple as they found something fascinating and lost track of time / air consumption.

[ /speculation ]

 

[Lobzilla]

[ speculation ]

Two inexperienced young men, diving in a totally new-to-them environment . . . perhaps it was as simple as they found something fascinating and lost track of time / air consumption.

[ /speculation ]

Both at the same time, without any attempt to ascend? If you are anywhere close to neutral and run OOG, all you have to do is finn up 5-20' feet - the rest of the ascent will take care of itself. Remember, how far we swam horizontally on a breath-hold without fins, buoyancy, and panic helping us?

[ speculation ]

Let's assume diver 1 looses track of time, exhales, tries to inhale to no avail (total OOG after he missed the increased resistance on the previous 2-5 breaths), tries to inflate BC to no avail (OOG !), does not kick back to surface, and drowns on the bottom (negatively buoyant from exhaling or kneeling at the bottom). How likely is it that diver 2 will just stay there and wait for the same fate? Or how likely is it that OOG happens to two divers at exactly the same time? Or how likely is it that diver 1 goes OOG, diver 2 donates, and both run eventually OOG without one of them instinctively remembering that there is infinite air supply above?

[ /speculation ]


Just found another reason why students should NEVER be tough to kneel over-weighed on the bottom. If you run OOG in that negative buoyancy condition you are in much deeper dodo than necessary. (Dumping weight that you did not need in the first place is a solution to an unnecessary problem)

 

[Ken Kurtis]

But what if that gear (e.g., inflated BCD) is what's keeping the troubled diver on the surface of the water?

This is a valid question but let's consider it in the context of CA diving.

Because our water temps along the entire length of our coastline throughout the entire year range from mid-40s to upper-60s, we are ALWAYS wearing some sort of wetsuit or dryusit. So ditching the BC and the weights shouldn't present an I-can't-float issue because the buoyancy of the wetsuit or drysuit alone should keep you floating.

But what if you weren't wearing any neoprene because you were in warm water? Would the BC be the only thing that would be keeping you afloat? Maybe, maybe not.

If you're in really good shape and dive with just your bathing suit and a BC and no weights (because you're negatively buoyant), then (1) there are no weights to ditch in the first place, and (2) yes, the BC might be the only thing that keeps you floating at the surface.

But if you're not in such good shape (probably a large majority of divers) and you have some "natural buoyancy" (aka "body fat") then you likely can't sink without some weight. In that sense, it's effectively the same as if you have a wetsuit on since, without the weights, you will float. (How much you float obviously depends on a few factors like % body fat and others.) In this example you could ditch the weights and ditch the BC and your natural bouyancy should keep you at (or get you to) the surface.

But what this all really underscores for me is that perhaps (looking ahead to the possibility of an emergency where you're unconscious and you WANT to be floating at the surface instead of drowning on the bottom) it may make sense even in very warm water to dive in at least a 3mm suit so that if you have to ditch everything, you know you've got something that will either keep you on the surface if you make it there on your own or will float you to the surface if you're still submerged and become unconscious.

- Ken

 

[Jax]

Both at the same time, without any attempt to ascend? If you are anywhere close to neutral and run OOG, all you have to do is finn up 5-20' feet - the rest of the ascent will take care of itself. Remember, how far we swam horizontally on a breath-hold without fins, buoyancy, and panic helping us?

[ speculation ]

Let's assume diver 1 looses track of time, exhales, tries to inhale to no avail (total OOG after he missed the increased resistance on the previous 2-5 breaths), tries to inflate BC to no avail (OOG !), does not kick back to surface, and drowns on the bottom (negatively buoyant from exhaling or kneeling at the bottom). How likely is it that diver 2 will just stay there and wait for the same fate? Or how likely is it that OOG happens to two divers at exactly the same time? Or how likely is it that diver 1 goes OOG, diver 2 donates, and both run eventually OOG without one of them instinctively remembering that there is infinite air supply above?

[ /speculation ]


Just found another reason why students should NEVER be tough to kneel over-weighed on the bottom. If you run OOG in that negative buoyancy condition you are in much deeper dodo than necessary. (Dumping weight that you did not need in the first place is a solution to an unnecessary problem)

[speculation]

If the divers were even on their air consumption - not so hard to imagine - the first guy goes OOG and they grab each other to air-share and ascend. The get up just a little ways, and the second tank goes dry. IF (big if) they were overweighted as new divers often are, they might not struggle to the surface.

Assumption - they both lose track of air, not hard to imagine. Assumption - they panic and don't drop weight, etc.

[/speculation]

 

[Ken Kurtis]

Lastly, I find the unqualified blanket-suggestion to ditch weight in ANY emergency troublesome.

Well, not I-can't-clear-my mask or I-just-lost-my-buddy . . .



But seriously folks . . .

Lobzilla raises a valid point. But I'd counter with the thought that the real problem is that divers RARELY ditch their weights. In the 8 years I've worked with the L.A. County Coroner as a forensic consultant for scuba fatalities, I can't rember a single instance where a troubled diver ditched weights. But we've got plenty of examples of dead divers on the bottom with weights firmly intact.

Would those people have survived had they ditched their weights and made it -even unconscious - to the surface? I don't know and there's no way to say one way or the other. But we we DO know is that they died with their weights on and those weights kept them on the bottom, making the prospect of a successful rescue at best harder and at worst impossible.

And even going back to Don's original point about waiting until you get to the surface to ditch weights, I think the problem is that divers THINK they have things under control or THINK they'll make it to the surface so there's no need to ditch and then they DON'T make it to the surface and now the weights become a death sentence as the weights drag them back down to the bottom.

Yes, there may be instances (overhead immediately comes to mind) where you don't want to ditch weights. But those aren't basic-diver environments. And even in CA kelp, I'd rather ditch weights and risk the possibility of entanglement on the way up than keep them on and risk the certainty of death on the bottom.

I think we need to do a better job of teaching students in basic classes to ditch weights routinely when things start getting out of hand. We do a good job of teaching mask clearance as a conditioned response. Why not do the same with recognizing emergency situations and weight ditching? (And for thoise of you who are instructors, ask yourself this: How many of you have students ditch weights and ascend either in the pool &/or ocean? And if you don't, are you short-changing them?)

I agree with Lobzilla that the "when to ditch " discussion is interesting but the refinements are an advanced skill, not a basic one. The basic skill should be (IMHO) to ditch weights earlier, not later.

In this particular accident (that started this thread), if these two young men had ditched their weights on the bottom, and even if they had floated up unconscious, I can't sit here and say with 100% certainty that the outcome would have been any different.

But I can say with 100% certainity that had they done so and floated to the surface, it would not have taken 40-50 minuters to locate them as it did with them on the bottom. And that alone might have improved their chances of survival.

- Ken