Diving incident at Eagles Nest Sink

[BabyDuck]

ok, question.

did diver 1 have his 95 manifolded into the jj system? but his little dil tank also on? so maybe the ip of the 95 happened to be higher and diver 2 drained the little tank and then they were both on the 95 and it was also drained? but wouldn't diver 1 still have had a breathable loop even though now he has nothing safe to add to it? I'm just having trouble seeing the connection if the 95 was entirely offboard so i'm assuming it was manifolded but both tanks were on. thoughts?

 

[catone]

It was attached to his rig via a QC6.

 

[Dan]

ok, question.

did diver 1 have his 95 manifolded into the jj system? but his little dil tank also on? so maybe the ip of the 95 happened to be higher and diver 2 drained the little tank and then they were both on the 95 and it was also drained? but wouldn't diver 1 still have had a breathable loop even though now he has nothing safe to add to it? I'm just having trouble seeing the connection if the 95 was entirely offboard so i'm assuming it was manifolded but both tanks were on. thoughts?

To answer your questions & perhaps follow up questions, first of all it's worth to read & reread (I did it 3x) the Statement of Facts written by Charlie Robertson on CDF, posted by PfcAJ on page 9 post #89.

"STATEMENT OF FACTS

1. Chris Rittenmeyer and Patrick Peacock started a dive at Eagle's Nest around 2:00 p.m. on Saturday, October 15, 2016. They were on JJ-CCRs with 95cf sidemount bailouts. Each diver had a scooter and an AL80 safety. They also towed a backup scooter. They had placed all their deco safeties in the cave the day before.
2. Chris and Patrick were both fully trained as Full Cave, Trimix, CCR, and DPV divers. Both divers had years of ocean and cave diving experience.
3. When the divers failed to return to deco at the anticipated time, their surface support buddy checked every 30 minutes until they were several hours overdue. Their buddy called Cave Country Dive Shop around 6:00 p.m. and spoke to Jon Bernot, who immediately loaded his vehicle and started driving to Eagle's Nest. While enroute, Jon called around and activated a response team of qualified and available cave divers.
4. Search Team 1, of Jon Bernot and Charlie Roberson, got underway around 11:00 p.m. to search the upstream passage, which was the dive plan according to the buddy. Team 1 checked the habitat and spotted three O2 bottles at 20 ffw, four 50% at 70 ffw, and two 120 bottles on the top of the mound, all of which were untouched. Team 1 noticed that the 120 bottles were on the downstream side of the line but decided to go ahead and check the upstream since that was believed to be the dive plan. Team 1 scoured the entire upstream all the way to the far reaches of the Green Room, King's Challenge, and all the large passage and rooms. When Team I failed to find anything upstream, they proceeded to check the Lockwood tunnel to no avail. Team 1 surfaced around 3:30 a.m.
5. Search Team 2, of Ted McCoy and AJ Gonzales, got underway around 3:45 a.m. and headed downstream. They immediately found the two bodies on the exit side of the Pit in approximately 220-230 ffw. Team 2 fully documented the scene and took detailed notes for about 45 minutes before exiting.
6. Diver 1 was wearing his CCR but his bailouts were not in place. One empty 95 bailout was beside him and attached to his rig via a QC6 and the long hose was deployed. His loop was open and out of his mouth. The inhale side of the loop was crushed. He had 300 psi of O2 but no onboard diluent remaining. He did have a 13cf inflation bottle with gas remaining. He had no primary light head and his backup lights were not deployed. There was a single scooter near Diver 1 but it was unclipped and turned off.
7. Diver 2 was only wearing a drysuit, mask and fins and was positively buoyant. He had a backup light clipped off and dangling out of his pocket. No other bottles were nearby.
8. A full AL80 safety was located just on the exit side of the Pit restriction in 270 ffw but was not easily seen on the way out. The primary light head with e/o cord was also located on the exit side of the Pit restriction. Their other full AL80 safety was located beside another team’s full safety just downstream of the jump to the Lockwood tunnel.
9. Two 95 bailouts were located just on the far side of the Pit. Both were empty.
10. Recovery Team 1 brought both bodies to the top of the Ballroom and Recovery Team 2 brought both bodies to the surface on Sunday afternoon.
11. Diver 2's CCR, a 95 bailout, and two scooters were located on Monday morning just outside the restriction to Revelation Space in the Room of Dreams. The CCR loop was closed and appeared to be fully operational. The 95 bailout was full. Diver 2 had video lights for a GoPro plugged into his canister light.
12. The gear recovery team of Jon Bernot and James Draker removed all the gear from the cave and turned it over to law enforcement on Monday, October 17, 2016.

The nature of accident analysis is that it's critical of those involved. However, friends, family, and those involved in the recovery have many raw emotions regarding this loss. I ask that you keep this in mind as you proceed with a thorough and professional accident analysis.

Safe diving,
Charlie Roberson"

 

[kelemvor]

To answer your questions & perhaps follow up questions, first of all it's worth to read & reread (I did it 3x) the Statement of Facts written by Charlie Robertson on CDF, posted by PfcAJ on page 9 post #89.

Can be hard to find, and it's such an important post... Here's a link right to it.

Personally, I'm thankful for the discussion here. Even if it doesn't further the cause of solving the mysteries of this accident it has at least spurred thoughts I otherwise might not have had. Hopefully a few of the nuggets can be applied to my vastly less extreme diving.

 

[Bobby]

This is a good decision to make. Diver2 might have been in similar situation.

I believe that diver 2 made the decision to remove his unit after he was already in the restriction attempting to exit. The difference is that my configuration has me in OC SM when the RB is removed. Back then I had to adjust buoyancy however I still had buoyancy control of both myself with the SM cylinders on me and the CCR. My issue was poor buoyancy control of the CCR when changing depth, as I was going deeper it became negative, crashed, and caused the silt out. Today I have a better configuration that gives me better buoyancy control of the CCR when changing depth. With Diver 2, from the reports given, it seems that he was not setup for CCR removal and doing so left him without personal buoyancy control. Back in the day some of us would remove BM doubles to pass restrictions. I can tell you from experience that maintaining control was very difficult when coming out of any restriction into larger passage. If the CCR was dropped it is likely that a complete silt out occurred and the diver was uncontrollably buoyant.

From the reports it also seems both divers did the best they could in a horrible situation. Even after leaving a functional CCR and one of the 95 BO's (most likely due to an extreme silt out) they were ever so close. If they had found the staged BO at the bottom of the Pit or had a little more gas to make to the BO close to the top of the Pit they might have been able to get out. I agree, with what others have said, that removing the CCR likely led to loosing control of it and was the trigger for the incident. That decision though was likely the best of all bad options.

From experience I can say that reactions to a cascading event are different between solo and team diving. When solo diving you only need to think about yourself, when team diving the pressure of supporting your team adds a lot of complexity. I have had situations that were not truly a cascade, simply miscommunication, that were handled poorly by everyone in the team due to the pressure, felt by each team member, of supporting the team. Each cascading event is different and none of us know how we are going to react until we are actually there. I have had situations that I have handled without much fanfare and I've had situations that I've not handled properly. From the reports, it seems that this team worked to help each other and did an admirable job in a horribly bad situation.

 

[Dan]

Thanks clarifying my ignorance about type of CCR out there.

I was referring to your statement:

"... After a few minutes of working too hard to resolve the situation and allowing anxiety rise to an unacceptable level I was close to abandoning the CCR and exiting on OC. This is when I stopped all actions and just told myself to calm down, as long as I had the functioning CCR I had nothing but time"...

Is it not similar to the situation that Diver2 was facing?

Someone here, may be you (I lost track on whom, after 43 pages & 425 posts) mentioned about when you have CCR on, you have time to wait until the silt to settle enough to see a better opening to go through with the CCR on. After all, you were able to get in with the CCR on initially.

 

[kensuf]

Someone here, may be you (I lost track on whom, after 43 pages & 425 posts) mentioned about when you have CCR on, you have time to wait until the silt to settle enough to see a better opening to go through with the CCR on. After all, you were able to get in with the CCR on initially.

It can take substantial time for clay siltouts to clear. I've been to this particular restriction 24-48 hours after another team had a silt out there. It was still cloudy with only 1-3' of visibility.

The time benefit of the ccr would be the time to figure out how to get through it. The cost would be substantial deco penalty.

I think we all learned in openwater scuba to stop, think, act. The ccr gives you ample time to think.

 

[Dan]

I check the spec of JJ-CCR from A REBREATHER CHOSEN BY DEMANDING DIVERS - JJ-CCR
It has 34.2kg (75lbs) with 2x3L tanks or 19.8kg (44lbs) w/o tanks & soda lime. That's a lot of weight to balance underwater.

 

[tbone1004]

remember the amount of empty space inside of the rebreathers. while they are very heavy, mass and weight on land don't mean they are that negative in the water. *They're quite heavy if they flood...* but my DPV is 96lbs on land but is neutral in the water. It's big, it's heavy, but it "weighs" nothing when it is submerged.

 

[Capt Tom McCarthy]

ok, question.

did diver 1 have his 95 manifolded into the jj system? but his little dil tank also on? so maybe the ip of the 95 happened to be higher and diver 2 drained the little tank and then they were both on the 95 and it was also drained? but wouldn't diver 1 still have had a breathable loop even though now he has nothing safe to add to it? I'm just having trouble seeing the connection if the 95 was entirely offboard so i'm assuming it was manifolded but both tanks were on. thoughts?

The statement said that the QC6 offboard connection was found still connected to the final bailout cylinder which was used. Both onboard and offboard 95 were drained. You would have a breathable loop for small period of time, for sure, assuming that you don't have to descend, clear a mask or accidentally purge any loop volume (which in a situation like this is highly possible).

At that point you'd have pure oxygen remaining as the only addition gas. Just based upon the close proximity that the divers were found I would go this route. There is always the possibility that Diver 1 had a hypoxic/hyperoxic event as well but we wont know more until the report is finished.

Again, while sometimes it's an interesting learning exercise to talk about what could have happened, based upon facts we know, at this point it is still pure speculation until ALL the facts are put together. Even then we may not know everything.