OC BO Planning

diverrob · 7th August 2009, 05:00

OK here is a lesson on why it is a good idea to try and match your BO profile with your CCR profile. The plan was for a 180’/30 min CCR dive in open water on a wreck. There were three CCR divers and we were using team BO. Divers had Tx 15/40 in their Dill ad carried a 30 of Tx 15/40 for a deep BO. The other BO gasses were Nx 36, Nx 60 and Nx 80 all of which were 40’s. The dive went as planned until the assent when one of the divers started to act strange (lots of flushing and no movement up to the stop at 110’). I went down to see if he was OK and saw his PPO2 at 0.4 and shouted to him to bring it up and start the assent. He did not seem to respond and was having difficulty breathing, he was also confused and could not find his Kiss valve to bring up his PPO2. I shouted at him to BO and he did not seem to respond so I took my deep BO and shoved it in his face. He first tried to push it away in his confusion but after a couple of seconds did take it and went OC. Still confused we had to haul him up to the first stop at 110’ and switched to the 36%. Now he was starting to act a bit more normal and we carried on with the rest of the deco following the other two CCR computers. The diver in distress was unable to switch to OC on his computer and by the time we had the situation under control it was too late to do it anyway. We all knew that our OC and CCR profiles were within 5 min of each other so we felt OK to carry on with the deco following the CCR divers profile (Pursuit set to GF 10/75 set point 1.2). The rest of the deco was fine and when we got to the final stop (15’) we finished the CCR plan and I went to the boat and got the 30 of 100% I have for emergencies. I went back down to 15’ and switch the OC diver from 80% to 100%, we stayed an extra 10min on 100% and then ascended to the surface. The OC diver was asymptomatic and continued to breath 100% for the next 30-40min on the surface. Everything worked out in the end and no one was hurt. The reason for the BO and difficulty on the bottom is thought to be a CO2 hit. The cause of the hit is still unknown, the scrubber was soaked with seawater post dive but we think that was from the BO and not a leak in a seal. It could have been a bad check valve as well but of course everything checked out during the post dive inspection.

scubanimal · 7th August 2009, 05:21

Glad to hear everything worked out and your buddy is ok. Sounds like you're a great buddy to have.

This incident reflects near what I experienced and one of the reasons I'm a big advocate now for BOVs and external plug-in for gases. Agree that bailout plans should be close to CCR plan. I've been accused of carring too much BO gas, but thats what makes sense to me. CO2 hits are nasty, plenty of posts here that reinforce that. And it is really hard to go to OC when you get one. And being able to change to OC on your buddy, plus being able to plug in different gases as appropriate rather than having to take a reg out of your (or buddies) mouth. Dave ****** wrote a post that describes a very versatile setup that meets those needs, you might want to read.

Good work, and as you mod your future dives based on lessons learned I hope you'll post your thoughts on your changes.

sensor330 · 7th August 2009, 15:08

What wasn't really mentioned is that it was a two person rescue. Both Rob and I were pulling the guy up the up line as hard as we could as the stricken diver was so messed up he couldn't do it for himself; furthermore, in his CO2 haze he had wrapped his legs around the up line and wouldn't relax and let us help him. I believe that had it been a two person team the out come would've been very different.

Having witnessed this event I've got to say it really opened my eyes to how big of a danger CO2 can be.

Scott

jcmankat · 7th August 2009, 15:56

Few questions if I may: Hours on Sorb prior to dive (if any)? What type mesh and grade of sorb?? and any change in the normal packing procedure of the Sorb for this dive??

You guys rock pulling him up like that.. Props to you both

John

diverrob · 7th August 2009, 19:57

Quote: (Originally Posted by gato2)

Few questions if I may: Hours on Sorb prior to dive (if any)? What type mesh and grade of sorb?? and any change in the normal packing procedure of the Sorb for this dive??

You guys rock pulling him up like that.. Props to you both

John

He had new sorb (8-12 sonfolime), the packing is is question but not confirmed. There was a significant amount of settling seen during the post dive inspection but this could have been due to the flood during the BO.

Thanks for the questions, I hope this will show that BO planning is a must! Having 3 people made a world of difference and I have to say I was pretty shit scared for a while and I thank Scott for being the other one in the water (a very cool costumer

)

Rob

gerstl_ossi · 7th August 2009, 22:09

Quote: (Originally Posted by diverrob)

OK here is a lesson on why it is a good idea to try and match your BO profile with your CCR profile. The plan was for a 180’/30 min CCR dive in open water on a wreck. There were three CCR divers and we were using team BO. Divers had Tx 15/40 in their Dill ad carried a 30 of Tx 15/40 for a deep BO. The other BO gasses were Nx 36, Nx 60 and Nx 80 all of which were 40’s. The dive went as planned until the assent when one of the divers started to act strange (lots of flushing and no movement up to the stop at 110’). I went down to see if he was OK and saw his PPO2 at 0.4 and shouted to him to bring it up and start the assent. He did not seem to respond and was having difficulty breathing, he was also confused and could not find his Kiss valve to bring up his PPO2. I shouted at him to BO and he did not seem to respond so I took my deep BO and shoved it in his face. He first tried to push it away in his confusion but after a couple of seconds did take it and went OC. Still confused we had to haul him up to the first stop at 110’ and switched to the 36%. Now he was starting to act a bit more normal and we carried on with the rest of the deco following the other two CCR computers. The diver in distress was unable to switch to OC on his computer and by the time we had the situation under control it was too late to do it anyway. We all knew that our OC and CCR profiles were within 5 min of each other so we felt OK to carry on with the deco following the CCR divers profile (Pursuit set to GF 10/75 set point 1.2). The rest of the deco was fine and when we got to the final stop (15’) we finished the CCR plan and I went to the boat and got the 30 of 100% I have for emergencies. I went back down to 15’ and switch the OC diver from 80% to 100%, we stayed an extra 10min on 100% and then ascended to the surface. The OC diver was asymptomatic and continued to breath 100% for the next 30-40min on the surface. Everything worked out in the end and no one was hurt. The reason for the BO and difficulty on the bottom is thought to be a CO2 hit. The cause of the hit is still unknown, the scrubber was soaked with seawater post dive but we think that was from the BO and not a leak in a seal. It could have been a bad check valve as well but of course everything checked out during the post dive inspection.

Nice to hear that everything went OK. Well done guys.
Cheers Ossi

sea2summit · 7th August 2009, 22:18

Glad everybody made it back.
Probably get slammed for this but why not change one of the other SH's to bailout? Don't know about the SH HUD but I dive rEvo dreams which are independent of the computer so I could monitor my PPO2 off them and possibly get a better deco profile for the individual bailed-out with the computer. No bad on him, don't imagine I'd be able to do crap with my computer if I took a CO2 hit.

jkaterenchuk · 8th August 2009, 00:53

Quote: (Originally Posted by diverrob)

Thanks for the questions, I hope this will show that BO planning is a must! Having 3 people made a world of difference and I have to say I was pretty shit scared for a while and I thank Scott for being the other one in the water (a very cool costumer

)

Rob

I have said it many times and I will again. CCR Rescue is harder than anyone whom has not actually practised it can imagine. It should be part of a Mod 3 course and should be practised in control conditions. Scott already made note of the fact that two assist divers were needed to effect the rescue. Now imagine if the ascent had been without the aid of a upline. I also suspect the divers were utilizing drysuits which adds further complications.

John

jasondrake · 8th August 2009, 01:42

Agree CCR rescue is a nightmare. So many things to keep on top of.
I spent a few dives practising with friends and found that, assuming all carry adequate personal oc bailout, it makes a lot of sense to just switch rescuer and victim onto oc and finish out the dive that way. I found that ascending with an unresponsive diver, watching their po2, mine plus 6 inflating sources of buoyancy and considering deco obligations as well was too much. Too much for me to want to have to do in anger anyway. I decided that I will always carry personal oc bailout to finish the dive, and will switch oc as soon as I have a dependent needing to ascend. Any thoughts?

Of course this is only a possible consideration if everyone has enough gas.

Joshua Smith · 8th August 2009, 02:27

Quote: (Originally Posted by diverrob)

OK here is a lesson on why it is a good idea to try and match your BO profile with your CCR profile. The plan was for a 180’/30 min CCR dive in open water on a wreck. There were three CCR divers and we were using team BO. Divers had Tx 15/40 in their Dill ad carried a 30 of Tx 15/40 for a deep BO. The other BO gasses were Nx 36, Nx 60 and Nx 80 all of which were 40’s. The dive went as planned until the assent when one of the divers started to act strange (lots of flushing and no movement up to the stop at 110’). I went down to see if he was OK and saw his PPO2 at 0.4 and shouted to him to bring it up and start the assent. He did not seem to respond and was having difficulty breathing, he was also confused and could not find his Kiss valve to bring up his PPO2. I shouted at him to BO and he did not seem to respond so I took my deep BO and shoved it in his face. He first tried to push it away in his confusion but after a couple of seconds did take it and went OC. Still confused we had to haul him up to the first stop at 110’ and switched to the 36%. Now he was starting to act a bit more normal and we carried on with the rest of the deco following the other two CCR computers. The diver in distress was unable to switch to OC on his computer and by the time we had the situation under control it was too late to do it anyway. We all knew that our OC and CCR profiles were within 5 min of each other so we felt OK to carry on with the deco following the CCR divers profile (Pursuit set to GF 10/75 set point 1.2). The rest of the deco was fine and when we got to the final stop (15’) we finished the CCR plan and I went to the boat and got the 30 of 100% I have for emergencies. I went back down to 15’ and switch the OC diver from 80% to 100%, we stayed an extra 10min on 100% and then ascended to the surface. The OC diver was asymptomatic and continued to breath 100% for the next 30-40min on the surface. Everything worked out in the end and no one was hurt. The reason for the BO and difficulty on the bottom is thought to be a CO2 hit. The cause of the hit is still unknown, the scrubber was soaked with seawater post dive but we think that was from the BO and not a leak in a seal. It could have been a bad check valve as well but of course everything checked out during the post dive inspection.

Good job handling that one. I'll dive with you any time.

That said, I prefer to carry my own BO as much as possible- for that dive, I would probably have been carrying a 40 cf of trimix and an 80 of 40%...never hurts to have more.

7th August 2009, 05:00	#1 (permalink)
diverrob The Evolution of Diving Hybrid Meg MCCR Dolphin, Evolution Join Date: May 2005 Location: Victoria BC Canada Posts: 705	OC BO Planning OK here is a lesson on why it is a good idea to try and match your BO profile with your CCR profile. The plan was for a 180’/30 min CCR dive in open water on a wreck. There were three CCR divers and we were using team BO. Divers had Tx 15/40 in their Dill ad carried a 30 of Tx 15/40 for a deep BO. The other BO gasses were Nx 36, Nx 60 and Nx 80 all of which were 40’s. The dive went as planned until the assent when one of the divers started to act strange (lots of flushing and no movement up to the stop at 110’). I went down to see if he was OK and saw his PPO2 at 0.4 and shouted to him to bring it up and start the assent. He did not seem to respond and was having difficulty breathing, he was also confused and could not find his Kiss valve to bring up his PPO2. I shouted at him to BO and he did not seem to respond so I took my deep BO and shoved it in his face. He first tried to push it away in his confusion but after a couple of seconds did take it and went OC. Still confused we had to haul him up to the first stop at 110’ and switched to the 36%. Now he was starting to act a bit more normal and we carried on with the rest of the deco following the other two CCR computers. The diver in distress was unable to switch to OC on his computer and by the time we had the situation under control it was too late to do it anyway. We all knew that our OC and CCR profiles were within 5 min of each other so we felt OK to carry on with the deco following the CCR divers profile (Pursuit set to GF 10/75 set point 1.2). The rest of the deco was fine and when we got to the final stop (15’) we finished the CCR plan and I went to the boat and got the 30 of 100% I have for emergencies. I went back down to 15’ and switch the OC diver from 80% to 100%, we stayed an extra 10min on 100% and then ascended to the surface. The OC diver was asymptomatic and continued to breath 100% for the next 30-40min on the surface. Everything worked out in the end and no one was hurt. The reason for the BO and difficulty on the bottom is thought to be a CO2 hit. The cause of the hit is still unknown, the scrubber was soaked with seawater post dive but we think that was from the BO and not a leak in a seal. It could have been a bad check valve as well but of course everything checked out during the post dive inspection.
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7th August 2009, 05:21	#2 (permalink)
scubanimal Ian Martin rEvo, Vision Inspo, Mark VI Dolphin,Optima Join Date: May 2006 Location: San Diego Posts: 136	Re: OC BO Planning Glad to hear everything worked out and your buddy is ok. Sounds like you're a great buddy to have. This incident reflects near what I experienced and one of the reasons I'm a big advocate now for BOVs and external plug-in for gases. Agree that bailout plans should be close to CCR plan. I've been accused of carring too much BO gas, but thats what makes sense to me. CO2 hits are nasty, plenty of posts here that reinforce that. And it is really hard to go to OC when you get one. And being able to change to OC on your buddy, plus being able to plug in different gases as appropriate rather than having to take a reg out of your (or buddies) mouth. Dave ****** wrote a post that describes a very versatile setup that meets those needs, you might want to read. Good work, and as you mod your future dives based on lessons learned I hope you'll post your thoughts on your changes.
(Offline)

7th August 2009, 15:08	#3 (permalink)
sensor330 RBW Member Who cares A few Join Date: Feb 2005 Location: Victoria, British Columbia Posts: 964	Re: OC BO Planning What wasn't really mentioned is that it was a two person rescue. Both Rob and I were pulling the guy up the up line as hard as we could as the stricken diver was so messed up he couldn't do it for himself; furthermore, in his CO2 haze he had wrapped his legs around the up line and wouldn't relax and let us help him. I believe that had it been a two person team the out come would've been very different. Having witnessed this event I've got to say it really opened my eyes to how big of a danger CO2 can be. Scott
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7th August 2009, 15:56	#4 (permalink)
jcmankat RBW Member rEvo 3 MICRO FT rEvo 3 Standard HCCR, MEG 2.01 Join Date: Aug 2008 Location: US Posts: 804	Re: OC BO Planning Few questions if I may: Hours on Sorb prior to dive (if any)? What type mesh and grade of sorb?? and any change in the normal packing procedure of the Sorb for this dive?? You guys rock pulling him up like that.. Props to you both John
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7th August 2009, 19:57	#5 (permalink)
diverrob The Evolution of Diving Hybrid Meg MCCR Dolphin, Evolution Join Date: May 2005 Location: Victoria BC Canada Posts: 705	Re: OC BO Planning Quote: (Originally Posted by gato2) Few questions if I may: Hours on Sorb prior to dive (if any)? What type mesh and grade of sorb?? and any change in the normal packing procedure of the Sorb for this dive?? You guys rock pulling him up like that.. Props to you both John He had new sorb (8-12 sonfolime), the packing is is question but not confirmed. There was a significant amount of settling seen during the post dive inspection but this could have been due to the flood during the BO. Thanks for the questions, I hope this will show that BO planning is a must! Having 3 people made a world of difference and I have to say I was pretty shit scared for a while and I thank Scott for being the other one in the water (a very cool costumer) Rob
(Offline)

7th August 2009, 22:09	#6 (permalink)
gerstl_ossi Ossi eCCR Hybrid Homebuild pSCR RO80 Homebuild, LightMCCR Join Date: Dec 2006 Location: Italy Posts: 1,028	Re: OC BO Planning Quote: (Originally Posted by diverrob) OK here is a lesson on why it is a good idea to try and match your BO profile with your CCR profile. The plan was for a 180’/30 min CCR dive in open water on a wreck. There were three CCR divers and we were using team BO. Divers had Tx 15/40 in their Dill ad carried a 30 of Tx 15/40 for a deep BO. The other BO gasses were Nx 36, Nx 60 and Nx 80 all of which were 40’s. The dive went as planned until the assent when one of the divers started to act strange (lots of flushing and no movement up to the stop at 110’). I went down to see if he was OK and saw his PPO2 at 0.4 and shouted to him to bring it up and start the assent. He did not seem to respond and was having difficulty breathing, he was also confused and could not find his Kiss valve to bring up his PPO2. I shouted at him to BO and he did not seem to respond so I took my deep BO and shoved it in his face. He first tried to push it away in his confusion but after a couple of seconds did take it and went OC. Still confused we had to haul him up to the first stop at 110’ and switched to the 36%. Now he was starting to act a bit more normal and we carried on with the rest of the deco following the other two CCR computers. The diver in distress was unable to switch to OC on his computer and by the time we had the situation under control it was too late to do it anyway. We all knew that our OC and CCR profiles were within 5 min of each other so we felt OK to carry on with the deco following the CCR divers profile (Pursuit set to GF 10/75 set point 1.2). The rest of the deco was fine and when we got to the final stop (15’) we finished the CCR plan and I went to the boat and got the 30 of 100% I have for emergencies. I went back down to 15’ and switch the OC diver from 80% to 100%, we stayed an extra 10min on 100% and then ascended to the surface. The OC diver was asymptomatic and continued to breath 100% for the next 30-40min on the surface. Everything worked out in the end and no one was hurt. The reason for the BO and difficulty on the bottom is thought to be a CO2 hit. The cause of the hit is still unknown, the scrubber was soaked with seawater post dive but we think that was from the BO and not a leak in a seal. It could have been a bad check valve as well but of course everything checked out during the post dive inspection. Nice to hear that everything went OK. Well done guys. Cheers Ossi
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7th August 2009, 22:18	#7 (permalink)
sea2summit Wannabe...diven the best oNe Join Date: May 2007 Location: Ft. Lewis Posts: 486	Re: OC BO Planning Glad everybody made it back. Probably get slammed for this but why not change one of the other SH's to bailout? Don't know about the SH HUD but I dive rEvo dreams which are independent of the computer so I could monitor my PPO2 off them and possibly get a better deco profile for the individual bailed-out with the computer. No bad on him, don't imagine I'd be able to do crap with my computer if I took a CO2 hit.
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8th August 2009, 00:53	#8 (permalink)
jkaterenchuk RBW Member HammerMeg Kiss Classic, Inspiration Join Date: May 2006 Location: PA Posts: 2,863	Re: OC BO Planning Quote: (Originally Posted by diverrob) Thanks for the questions, I hope this will show that BO planning is a must! Having 3 people made a world of difference and I have to say I was pretty shit scared for a while and I thank Scott for being the other one in the water (a very cool costumer) Rob I have said it many times and I will again. CCR Rescue is harder than anyone whom has not actually practised it can imagine. It should be part of a Mod 3 course and should be practised in control conditions. Scott already made note of the fact that two assist divers were needed to effect the rescue. Now imagine if the ascent had been without the aid of a upline. I also suspect the divers were utilizing drysuits which adds further complications. John
(Online)

8th August 2009, 01:42	#9 (permalink)
jasondrake RBW Member homebuilt mccr Join Date: Nov 2005 Location: Completely homeless Posts: 183	Re: OC BO Planning Agree CCR rescue is a nightmare. So many things to keep on top of. I spent a few dives practising with friends and found that, assuming all carry adequate personal oc bailout, it makes a lot of sense to just switch rescuer and victim onto oc and finish out the dive that way. I found that ascending with an unresponsive diver, watching their po2, mine plus 6 inflating sources of buoyancy and considering deco obligations as well was too much. Too much for me to want to have to do in anger anyway. I decided that I will always carry personal oc bailout to finish the dive, and will switch oc as soon as I have a dependent needing to ascend. Any thoughts? Of course this is only a possible consideration if everyone has enough gas.
(Offline)

8th August 2009, 02:27	#10 (permalink)
Joshua Smith Nailer99 Megalodon Join Date: Jan 2007 Location: Seattle, WA, USA Posts: 689	Re: OC BO Planning Quote: (Originally Posted by diverrob) OK here is a lesson on why it is a good idea to try and match your BO profile with your CCR profile. The plan was for a 180’/30 min CCR dive in open water on a wreck. There were three CCR divers and we were using team BO. Divers had Tx 15/40 in their Dill ad carried a 30 of Tx 15/40 for a deep BO. The other BO gasses were Nx 36, Nx 60 and Nx 80 all of which were 40’s. The dive went as planned until the assent when one of the divers started to act strange (lots of flushing and no movement up to the stop at 110’). I went down to see if he was OK and saw his PPO2 at 0.4 and shouted to him to bring it up and start the assent. He did not seem to respond and was having difficulty breathing, he was also confused and could not find his Kiss valve to bring up his PPO2. I shouted at him to BO and he did not seem to respond so I took my deep BO and shoved it in his face. He first tried to push it away in his confusion but after a couple of seconds did take it and went OC. Still confused we had to haul him up to the first stop at 110’ and switched to the 36%. Now he was starting to act a bit more normal and we carried on with the rest of the deco following the other two CCR computers. The diver in distress was unable to switch to OC on his computer and by the time we had the situation under control it was too late to do it anyway. We all knew that our OC and CCR profiles were within 5 min of each other so we felt OK to carry on with the deco following the CCR divers profile (Pursuit set to GF 10/75 set point 1.2). The rest of the deco was fine and when we got to the final stop (15’) we finished the CCR plan and I went to the boat and got the 30 of 100% I have for emergencies. I went back down to 15’ and switch the OC diver from 80% to 100%, we stayed an extra 10min on 100% and then ascended to the surface. The OC diver was asymptomatic and continued to breath 100% for the next 30-40min on the surface. Everything worked out in the end and no one was hurt. The reason for the BO and difficulty on the bottom is thought to be a CO2 hit. The cause of the hit is still unknown, the scrubber was soaked with seawater post dive but we think that was from the BO and not a leak in a seal. It could have been a bad check valve as well but of course everything checked out during the post dive inspection. Good job handling that one. I'll dive with you any time. That said, I prefer to carry my own BO as much as possible- for that dive, I would probably have been carrying a 40 cf of trimix and an 80 of 40%...never hurts to have more. __________________ -Joshua Smith, Seattle, WA Quote: (Originally Posted by aainslie) 1) The reberather should accompany the diver underwater. 2) The rebreather should contain a carbon dioxide absorbent product. 3) The rebreather should be switched on. 4) The rebreather should have no leaks.
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