2 Dead, 2 Injured in German lake

[Diver0001]

The depth of 50m and the exact location of the dive were confirmed by the divers of the other buddy teams.

According to the divers, the were not diving along the wall, but over a ledge that extends in front of the wall and slopes down to 50+ meters.

Unfortunately I don´t have any more answers, it´s all in the facebook link posted above.

So you can definitely confirm that they were actually diving at 50m?

R..

 

[Ayisha]

Both valves? was he using a Y or H valve?

- Everyone had cold-water compatible regulators with two separate 1st stages

bold added

It sounds like an H valve to me.

 

[Ayisha]

Freeflow dictates valve shutdown, does it not?

Actually, most divers were probably taught to breathe off a freeflow while ascending. The fear by some agencies about shutting down the valve tends to be that the diver's tank is off and they may get separated from the donor buddy. Couple this potential separation with not teaching or relaying the importance of being able to reach and turn your own valve on u/w and it can be a recipe for disaster...

It tends to be after the o/w course, when you start reading/listening to other ways, that you hear about switching to your buddy's back-up (or your own redundant tank) and shutting down your backgas valve until it thaws at a shallower depth - or feathering the valve until it thaws on the way up. And then switching back to your primary reg.

 

[Blue Sparkle]

Read the above post. 20 years ago this config was the norm, as mentioned.

R..

Thanks for the explanation. I understand what you mean about the "twist" - at first my buddy experimented with running his alternate regulator around from the left ("modern OW" style where he would donate the reg he was not using, which was on a slightly longer hose), for this same reason (but later changed it over to the more usual way).

I guess what threw me in this case was the fact that (IIRC) they were mentioned to be "short" hoses with "upside down regulators," which struck me because why would you have short hoses to donate? (There may be a good reason; I'm just saying why it made me think Hmm?)

 

[Jax]

Actually, most divers were probably taught to breathe off a freeflow while ascending. The fear by some agencies about shutting down the valve tends to be that the diver's tank is off and they may get separated from the donor buddy. Couple this potential separation with not teaching or relaying the importance of being able to reach and turn your own valve on u/w and it can be a recipe for disaster...

It tends to be after the o/w course, when you start reading/listening to other ways, that you hear about switching to your buddy's back-up (or your own redundant tank) and shutting down your backgas valve until it thaws at a shallower depth - or feathering the valve until it thaws on the way up. And then switching back to your primary reg.

Read back --- they were on "H" or "Y" valves. You shut down the valve when you have a free-flow. Two reg sets, two valves, one tank.

 

[Ayisha]

Read back --- they were on "H" or "Y" valves. You shut down the valve when you have a free-flow. Two reg sets, two valves, one tank.

I know it was an H or Y valve and shutting down the freeflowing valve would be correct, but your statement was in a separate paragraph and sounded like it related to freeflows in general:

Freeflow dictates valve shutdown, does it not?

 

[Jax]

I know it was an H or Y valve and shutting down the freeflowing valve would be correct, but your statement was in a separate paragraph and sounded like it related to freeflows in general:

Nope, just discussing the topic at hand.

 

[Divedaily]

A couple of comments/questions (see below)

- Maximum depth of the dive was 50 meters, along a ledge in front of the drop-off at E5
How was this determined?
- Maximu depth at the site is 50m. Alas they couldn't have gone deeper (or they had to bring a shovel)

- The tank of victim1 contained 65bar and the valve of his primary 1st stage was shut
This is highly irregular. Is there a theory as to how this could have happened?
- Not irregular at all, standard procedure when you have a frozen first stage

- The tank of victim2 was empty, both of his valves open
Both valves? was he using a Y or H valve?
- My GUESS would be Y-Valve. 90% of people I saw diving at Hemmoor (non-tec) were diving Y-Valves

- The official theory is that one of the divers probably encountered a free-flow. etc etc blah blah blah.
Is there any evidence for this or is it just a theory?
- the fact that one valve was shut could be considered evidence as this is the standard procedure for a frozen first stage, it's hard to imagen another reason for the valve to be closed

- they would have lost much of the suits buoyancy at 50 meters.
I'm still very curious if there is any EVIDENCE that they were diving at 50m aside from the fact that this is where the bodies were found..... don't forget, this is a wall dive and the wall extends from 50m all the way to the surface. I'm not saying they couldn't have been diving at 50m but without clear evidence to the contrary I will continue to resist the assumption that since the bodies were found at 50m that this is were they intended to be diving.
- It could very well be that the problem started shallower and they did descend without noticing, trying to solve the frozen first stage

- Also since the inflator of victim1 was attached to the first stage that was shut off, he would be unable to use the inflator to create positive lift. Since they did not drop their weights, they were unable to ascend to the surface.
This is, obviously, highly irregular. Has it been established beyond doubt that the 1st stage of this diver was turned off during the incident at hand? If so this could be a very important clue.
- as there was nobody present when the incident happened (at least alive, maybe Fred was there from the beginning) there will be no proof as such. But once again, turning of a first stage when its frozen is the recommended thing to do. Its hardly feasible that they would have turned it of before the incident (a frozen first stage would mean the end of the dive, if that let to the incident that caused their deaths I consider it to be part of the incident), let alone afterwards....

- So much for this theory, which makes a lot of sense and sounds conclusive.
Really? To me it only raises more questions.
- there will always be questions. But it sounds plausible to me as well. I've dived Hemmoor and I can imagen that if things start to go wrong, one thing very quickly leads to another and thats just what is described here.
Biggest mistake seems to have been the inflatorhose on the same first stage as the main reg (as a frozen main first stage means losing both air and bouancy at the same time)

Kind Regards