Walchensee (Germany) - Diver panics at 30m dies, buddies surface too quickly

[DevonDiver]

The article more than implies that the fatality was caused by a regulator unsuitable for cold water diving. That suggests a 1st stage freeflow at depth as the triggering factor.

Freeflow regulator breathing is an Open Water level skill.

It's important to recognize that whilst the freeflow was a trigger; an inability to perform entry-level competencies formed the link in the accident chain that led to a fatality.

A second link in that accident chain is the opportunity to air-share. With 12 divers in the group, there was ample opportunity for someone to provide assistance and air to the diver with complications. An air-sharing ascent would have averted the catastrophe, irrespective of the free-flow. This was not successfully performed (attempted?) by any of the divers present.

Contingency/emergency skills are meant to mitigate against such forseeable incidents turning into accidents where injury or death occur.

Insufficient training at the onset, coupled with insufficient maintenance of critical emergency skills is... I believe...the major issue to be highlighted.

Put simply, recreational divers should not die from freeflow events.

Other factors worth considering is the training/experience level of the participant group divers versus the level of supervision. The OP mentions a group size of 12 with a (singular?) leader. A single dive leader could not be expected to safely and sufficiently supervise and/or intervene with that size of group, especially in low visibility. That points to flawed dive leadership.

There's been no mention of the certification/training/experience levels of those involved - but the fact that one diver was unable to deal with a freeflow, provoking two other divers into rapid ascents.... hints towards a very inexperienced and/or under-trained group.

 

[DevonDiver]

He reckons the divers were about 15 minutes into the dive,

That seems like quite a slow onset for regulator icing... such problems normally present themselves very quickly into the dive. That's usually because a regulator has 'frosted' in cold surface/dry air, then developed ice rapidly upon submersion.

Leaving the scuba equipment exposed pre-dive can cause rapid icing.... as can pre-breathing (buddy check) the regulator dry, in sub-zero temperatures.

However, if the reg was 'warm' at the start of the dive (came swiftly from a warmed car, or building, for example), then the onset of ice formation in the 1st stage can be slower - over the course of the dive.

Again.... a leader-to-group size of 12 shows little evidence that the issue of cold-water freeflow was anticipated in any risk assessment prior to the dive.

Any cold-water diving activity, even with 'cold-water regulators' should anticipate the possibility of regulator free-flow... and participants should be briefed (reminded) on the appropriate contingencies for dealing with this event.

Given that a freeflow can be shocking in terms of bubbles/confusion....both for the victim and potentially for those around them.... the leader/group should be confident in their psychological preparedness to deal with that situation.

 

[Ayisha]

That seems like quite a slow onset for regulator icing... such problems normally present themselves very quickly into the dive.

I've seen it happen later in a dive once before, although freeflows usually do occur early in a dive. After uneventful cold water diving for two days in Tobermory, Ontario a few years ago, my new buddy had a massive freeflow as soon as we hit 114 feet on the Forest City on the third day. We thought everything might be ok on the second dive that day on the Arabia right up until the end when we were making our way back at around 100 feet to the ascent line and he had a freeflow again. He had his reg checked and de-tuned after that. That's the only time I've seen a freeflow later in the dive.

 

[rx7diver]

That seems like quite a slow onset for regulator icing... such problems normally present themselves very quickly into the dive.

It (i.e., having a free flow later in a dive) has happened to me, as well. I wrote about it a while ago here: Free Flow Incidents.

Safe Diving,

rx7diver

 

[Dan]

So, is it a common practice to have redundancy (dual 1st stages) when you dive in cold water?

 

[Storker]

I guess it depends on your definition of "cold water". More than half of my clubmates dive single tank rigs with a normal 1 1st + 2 2nd reg config. And water temps down to 3-4C (37-39F) is quite common during winter here. Quite a few use recreational doubles, but without any training in manipulating the valves underwater and often without an isolation valve on the manifold.

However, as I've mentioned upthread, practically no-one dives without a cold-water compatible reg set.

A 2nd stage freeflow after surfacing is more or less the standard when it's below freezing, but I still haven't seen or experienced a 1st stage freeflow. A 2nd stage freeflow under those condtions is just a minor annoyance.

 

[rx7diver]

So, is it a common practice to have redundancy (dual 1st stages) when you dive in cold water?

Not uncommon. But prudent. One first stage for the BC, and the other first stage for the dry suit. In the case of a free flow, switch to the other regulator, and shut down the valve of the offending regulator. (You will still be able to power inflate something.) Note: You *must* be able to readily reach both valve knobs.

EDIT: I am specifically referring to single tank recreational diving using a Y-valve (my preference) or an H-valve.

Safe Diving,

rx7diver

 

[Ayisha]

So, is it a common practice to have redundancy (dual 1st stages) when you dive in cold water?

In my buddy's case, I had a back mounted pony bottle and gave him my reg and I used my pony to not cause too great a demand on my main reg with both of us breathing it in cold water, around 40F/4C. Although my reg is environmentally sealed and has never free flowed, I'd rather not risk both of us breathing it if we didn't have to. He was a very heavy breather which likely contributed to his freeflows. Up to the time of the freeflows, he was also sometimes inflating his BCD and inhaling at the same time, as well as holding the inflator button down rather than just using short bursts, which can all potentially create more demand on a reg than it can handle in very cold water.

A lot of divers around Ontario dive manifolded doubles, but at the very least, use environmentally sealed regs. I see a lot of stage or pony bottles. I can't say I've seen too many H-valves.