Diving incident at Eagles Nest Sink

[PfcAJ]

Either stuck on the way out, or on the way in with an abort & turn-the-dive call.

The pertinent questions are why Diver2 couldn't find & retrieve the CCR and/or at least -the critical fourth 95cf bailout cylinder after passing through the Revelation restriction; or why he wasn't able to push the dismounted CCR/bailout 95 tank unit through ahead of him as he was clearing the restriction. . . (?)

I know that getting back into a rebreather underwater when pinned to the ceiling is pretty hard and very easy to cock up.

 

[Dsix36]

Ok, I guess I may as well post my guess of what happened in view of my previous experiences there.

The dive was planned well with plenty of BO gas. The divers had the certs to do the dive and had been in Eagles Nest before. This leads me to believe that nobody took of a rebreather to get through the restriction.

MY OPINION:

They went through the restriction and did their dive into Revelation Space. Upon their return to the restriction the vis was either not very good or the first diver out mucked it up for the second diver. The second diver had difficulty getting out the restriction either by going on the wrong side of the line or being in too much of a heads up position and his rebreather not clearing the ceiling. After several minutes of trying to get out the diver decided that he must remove his rebreather to get out. Since his Bo is also clipped to the same harness then he effectively becomes no mount at this point. He is buoyant as hell but the ceiling works in his favor. He pushes the rebreather and tank through the restriction and his buddy helps pull them out. by the time the diver is out of the restriction he has probably pretty much used up that entire tank and the visibilty is completely gone in that area and the silt cloud is bellowing into the room of dreams. As the diver trys to locate and get his RB back on his buoyancy takes him on a hell ride to the ceiling with his BO tank and his buddy goes to the rescue with his own BO. As they float at the ceiling they see nothing through the silt below them and decide to exit relying on their BO and staged tanks. I highly doubt that either of them even looked at their deco obligation until this time.

Pick it apart all you want, I have not interest in trying to justify my thoughts. The fact that they were still together until the end tells me that regardless of how things went, they worked together and did everything to the best of their ability, knowledge, and experience to stay alive.

I believe, as others have already said, that the fatal mistake was in not taking the time needed to locate and get back into the rebreather. It is entirely possible that due to the circumstances that this was either not a possibility or was perceived as such in one or both of their minds.

 

[Kevrumbo]

Another good possibility. Being plastered on the ceiling due to the positive buoyancy, it would be easier to do.

But again in a silt-out contingency, you've got one hand with positive contact on the penetration line:

IOW, the act of pushing through a dismounted CCR/bailout 95 while holding onto a penetration line through a restriction would be overwhelming. . .

 

[PfcAJ]

But again in a silt-out contingency, you've got one hand with positive contact on the penetration line:

IOW, the act of pushing through a dismounted CCR/bailout 95 while holding onto a penetration line through a restriction would be overwhelming. . .

It's not too crazy to maintain line contact when manipulating gear.

 

[cerich]

I don't think that's what AJ and Liteheaded had in mind when they made their statements. I think what they were trying to say is there's no way for someone whose experience is limited to a maximum four hour total run-time to understand and appreciate what is involved in dives that breach 7-10 hours.

Having done a half-dozen dives in the 6-7 hour range, I would agree with them that there is a difference in going from 4 to 6 hours. I can comfortably do a 4 hour dive any day of the week with very little extra preparation and little extra than I would take on just about any run of the mill cave dive, but on the 6 hour dives there are more things to consider. You have to consider things like nutrition (marathoners call it "bonking"), fluid intake (you need to re-hydrate on the dive), thermal stress (you're going to get cold on a 6 hour dive even in a perfectly functioning drysuit), and even just the mental aspect of knowing you have 5+ hours of mandatory decompression before you can surface.

It's easy to speak in hypotheticals and say "well I could do this" if you've got no frame of reference to know what it really takes to do that.

Ken, are you contending that this was a planned 6-7 hour dive? The jj has a rated 180 mins at 100m on the canister. I can't imagine the deco gas they placed was for planned use but bail out.

Edit- looks like there is a extended run script Ber for the JJ that will go to 6 hours, however based on the other diver that was there that day with them but doing a solo dive not as extreme who said that they entered the water at 2pm with a plan to check in at a predetermined place in the water at 3pm. Doesn't sound like a 6-7 hour run time was planned.

I suspect their planned run time was in the 3-4 hour range. Obviously at the depths planned any extra time can push the run to the 6-7 easily..and you are looking at scrubber duration issues, thermal, oc bailout and deco gas considerations etc.

As you know as well as anybody, dives like that are not even in the same league as dives to above 200.

 

[KevinNM]

Ok..assure me with math. We k ow how many cylinders of staged deco gas they had..regardless of how much deco they racked up by the extra time at depth, their deco gas supply would have still limited their deco.

They had a support diver. He would have called up Cave Country Dive Shop and told them his buddies had a major problem and are stuck with a flooded drysuit and not enough deco gas and I suspect things would start happening.

 

[Dan]

Ok, I guess I may as well post my guess of what happened in view of my previous experiences there.

The dive was planned well with plenty of BO gas. The divers had the certs to do the dive and had been in Eagles Nest before. This leads me to believe that nobody took of a rebreather to get through the restriction.

MY OPINION:

They went through the restriction and did their dive into Revelation Space. Upon their return to the restriction the vis was either not very good or the first diver out mucked it up for the second diver. The second diver had difficulty getting out the restriction either by going on the wrong side of the line or being in too much of a heads up position and his rebreather not clearing the ceiling. After several minutes of trying to get out the diver decided that he must remove his rebreather to get out. Since his Bo is also clipped to the same harness then he effectively becomes no mount at this point. He is buoyant as hell but the ceiling works in his favor. He pushes the rebreather and tank through the restriction and his buddy helps pull them out. by the time the diver is out of the restriction he has probably pretty much used up that entire tank and the visibilty is completely gone in that area and the silt cloud is bellowing into the room of dreams. As the diver trys to locate and get his RB back on his buoyancy takes him on a hell ride to the ceiling with his BO tank and his buddy goes to the rescue with his own BO. As they float at the ceiling they see nothing through the silt below them and decide to exit relying on their BO and staged tanks. I highly doubt that either of them even looked at their deco obligation until this time.

Pick it apart all you want, I have not interest in trying to justify my thoughts. The fact that they were still together until the end tells me that regardless of how things went, they worked together and did everything to the best of their ability, knowledge, and experience to stay alive.

I believe, as others have already said, that the fatal mistake was in not taking the time needed to locate and get back into the rebreather. It is entirely possible that due to the circumstances that this was either not a possibility or was perceived as such in one or both of their minds.

This scenario makes a lot of sense.

 

[cerich]

They had a support diver. He would have called up Cave Country Dive Shop and told them his buddies had a major problem and are stuck with a flooded drysuit and not enough deco gas and I suspect things would start happening.

NO they didn't, they had another diver in the system who was doing a solo dive with a less extreme profile.

Plus..did somebody move cave country dive shop even anywhere close to the nest?

 

[Kevrumbo]

Ok, I guess I may as well post my guess of what happened in view of my previous experiences there.

The dive was planned well with plenty of BO gas. The divers had the certs to do the dive and had been in Eagles Nest before. This leads me to believe that nobody took of a rebreather to get through the restriction.

MY OPINION:

They went through the restriction and did their dive into Revelation Space. Upon their return to the restriction the vis was either not very good or the first diver out mucked it up for the second diver. The second diver had difficulty getting out the restriction either by going on the wrong side of the line or being in too much of a heads up position and his rebreather not clearing the ceiling. After several minutes of trying to get out the diver decided that he must remove his rebreather to get out. Since his Bo is also clipped to the same harness then he effectively becomes no mount at this point. He is buoyant as hell but the ceiling works in his favor. He pushes the rebreather and tank through the restriction and his buddy helps pull them out. by the time the diver is out of the restriction he has probably pretty much used up that entire tank and the visibilty is completely gone in that area and the silt cloud is bellowing into the room of dreams. As the diver trys to locate and get his RB back on his buoyancy takes him on a hell ride to the ceiling with his BO tank and his buddy goes to the rescue with his own BO. As they float at the ceiling they see nothing through the silt below them and decide to exit relying on their BO and staged tanks. I highly doubt that either of them even looked at their deco obligation until this time.

Pick it apart all you want, I have not interest in trying to justify my thoughts. The fact that they were still together until the end tells me that regardless of how things went, they worked together and did everything to the best of their ability, knowledge, and experience to stay alive.

I believe, as others have already said, that the fatal mistake was in not taking the time needed to locate and get back into the rebreather. It is entirely possible that due to the circumstances that this was either not a possibility or was perceived as such in one or both of their minds.

But again in a silt-out contingency, you've got one hand with positive contact on the penetration line:

IOW, the act of pushing through a dismounted CCR/bailout 95 while holding onto a penetration line through a restriction would be overwhelming. . .

It's not too crazy to maintain line contact when manipulating gear.

So Diver2 pushes through the dismounted CCR/95 bailout unit but inadvertently fumbles it away into the silt cloud after clearing Revelation Restriction, as he floats up to the ceiling. . .

 

[cerich]

Going thru low and silty no mount passage is not easy when planned, using properly thought out and configured equipment for no mount. An unplanned no mount in those conditions is exceptionally dangerous. Once out of the no mount major restriction buoyancy and gear control becomes an immediate challenge even in planned no mount diving..in unplanned no mount...:-(