Bailout after deep dive and IBCD

PCDiver · 10th August 2007, 08:15

OK, let me give some extra info why this question came up.

We were discussing a deeper reef dive on the Red Sea from a liveaboard. The entire week dives will be around 60 - 70 meters. This dive will be to 100 meters. We have the following challenges:

1. He is very expensive in Egypt (500€ for a 50 liter), so we try to limit the different deco gasses that we use during the week.
2. We can only take two tanks each because there are not enough bailout tanks for the 4 of us.
3. There is chance of strong currents, therefore everyone will take its own tanks.
4. 20 minutes will probably not happen. This will rather be a long multilevel dive with 5 to 10 min at 100, 5 minutes at 80, 5 minutes at 60, ...
5. Using 50/25 instead of EAN50 will add 27 minutes to the deco time according to V-Planner

Dave O · 10th August 2007, 14:55

PC,

I'm not trying to be glib, but that's the price you pay. Either you risk the possible effects of IBCD on 50%, or you add some He and have an extended deco profile. Take your pick.

Another option is to use 70% for deco. This should have a very small N2 spike, and about the same deco as 50%. However, you may need more bottom mix.

Lilou6 · 10th August 2007, 17:56

Try with a 50/10 triox i think that probably solve your problem (deco time and price of HE) with a limited risk of IBCD ...

Lilian

PCDiver · 10th August 2007, 19:50

Quote: (Originally Posted by Lilou6)

Try with a 50/10 triox i think that probably solve your problem (deco time and price of HE) with a limited risk of IBCD ...

Lilian

That would certainly work. We can also buffer the N2 spike by going to TX15/50 for five or so minutes.

Digger · 10th August 2007, 20:04

I was told in my local centre the other day that a 50/20 mix had to be the strangest mix they'd ever blended on purpose. I thought it might just be me doing it, but it seems there's loads of you!

The other thing is it makes the tanks ride just nicely, the 20% He just makes them a little bit lighter when getting above 200 bar.

Digs.

Lilou6 · 10th August 2007, 21:28

For PCDiver,

Like we say in france i think you want the butter, the money of the butter and the ass of the cremiere ( i don't know if this is the right word in english)

.

Lilian

***Decodiver*** · 10th August 2007, 21:47

Quote: (Originally Posted by Lilou6)

For PCDiver,

Like we say in france i think you want the butter, the money of the butter and the ass of the cremiere ( i don't know if this is the right word in english)

.

Lilian

LMFAO! have some green.

Translated for Lilian.

You want your cake and to eat it and the arse of the woman that made the cake too!

PCDiver · 11th August 2007, 07:30

Quote: (Originally Posted by Decodiver)

LMFAO! have some green.

Translated for Lilian.

You want your cake and to eat it and the arse of the woman that made the cake too!

The

of the

will be fine ... No cake ... I'm on a diet.

Lilou6 · 11th August 2007, 12:06

The woman who make the cake to me have this tool

Lilian

***ScubaDadMiami*** · 11th August 2007, 19:32

I currently go with what Dave O suggests. I go on my bottom mix, and then I make a switch to EANx 70. I really don't want to start carrying more than two offboard tanks. I also do not want to have to depend on tanks hung from the boat or line in case I can't get to that location. So, the intermediate mix variation is not for me.

BTW, going a a helium mix at a deeper depth (such as 50/25, etc.) works great. It is just a question of the logistics of how much gas you need to carry in each tank for the profile.

10th August 2007, 08:15	#11 (permalink)
PCDiver Submerge Productions Current Rebreather/s: Inspiration Vision Other Rebreather/s: Inspiration Classic Join Date: Feb 2005 Location: Belgium Posts: 938	Re: Bailout after deep dive and IBCD OK, let me give some extra info why this question came up. We were discussing a deeper reef dive on the Red Sea from a liveaboard. The entire week dives will be around 60 - 70 meters. This dive will be to 100 meters. We have the following challenges: 1. He is very expensive in Egypt (500€ for a 50 liter), so we try to limit the different deco gasses that we use during the week. 2. We can only take two tanks each because there are not enough bailout tanks for the 4 of us. 3. There is chance of strong currents, therefore everyone will take its own tanks. 4. 20 minutes will probably not happen. This will rather be a long multilevel dive with 5 to 10 min at 100, 5 minutes at 80, 5 minutes at 60, ... 5. Using 50/25 instead of EAN50 will add 27 minutes to the deco time according to V-Planner
(Online)

10th August 2007, 14:55	#12 (permalink)
Dave O Wreck Diver Current Rebreather/s: Sport Kiss Classic Kiss Other Rebreather/s: Sport Kiss Join Date: Aug 2007 Location: NJ Posts: 122	Re: Bailout after deep dive and IBCD PC, I'm not trying to be glib, but that's the price you pay. Either you risk the possible effects of IBCD on 50%, or you add some He and have an extended deco profile. Take your pick. Another option is to use 70% for deco. This should have a very small N2 spike, and about the same deco as 50%. However, you may need more bottom mix.
(Offline)

10th August 2007, 17:56	#13 (permalink)
Lilou6 New Member Current Rebreather/s: Optima Other Rebreather/s: Not Bought Yet Join Date: Jun 2007 Location: South of the france Posts: 47	Re: Bailout after deep dive and IBCD Try with a 50/10 triox i think that probably solve your problem (deco time and price of HE) with a limited risk of IBCD ... Lilian
(Offline)

10th August 2007, 19:50	#14 (permalink)
PCDiver Submerge Productions Current Rebreather/s: Inspiration Vision Other Rebreather/s: Inspiration Classic Join Date: Feb 2005 Location: Belgium Posts: 938	Re: Bailout after deep dive and IBCD Quote: (Originally Posted by Lilou6) Try with a 50/10 triox i think that probably solve your problem (deco time and price of HE) with a limited risk of IBCD ... Lilian That would certainly work. We can also buffer the N2 spike by going to TX15/50 for five or so minutes.
(Online)

10th August 2007, 20:04	#15 (permalink)
Digger Custom Title Allowed! Current Rebreather/s: Inspiration Classic Other Rebreather/s: Not Bought Yet Inspiration Classic Classic Kiss Join Date: Feb 2005 Location: Midlands UK Posts: 206	Re: Bailout after deep dive and IBCD I was told in my local centre the other day that a 50/20 mix had to be the strangest mix they'd ever blended on purpose. I thought it might just be me doing it, but it seems there's loads of you! The other thing is it makes the tanks ride just nicely, the 20% He just makes them a little bit lighter when getting above 200 bar. Digs.
(Offline)

10th August 2007, 21:28	#16 (permalink)
Lilou6 New Member Current Rebreather/s: Optima Other Rebreather/s: Not Bought Yet Join Date: Jun 2007 Location: South of the france Posts: 47	Re: Bailout after deep dive and IBCD For PCDiver, Like we say in france i think you want the butter, the money of the butter and the ass of the cremiere ( i don't know if this is the right word in english) . Lilian
(Offline)

10th August 2007, 21:47	#17 (permalink)
*Decodiver* Administrator Current Rebreather/s: Megalodon Ouroboros rEvo Other CCR Other Rebreather/s: Inspiration Classic Inspiration Vision Evolution Sport Kiss Classic Kiss rEvo Other CCR Join Date: Jan 2005 Location: Geneva Posts: 2,179	Re: Bailout after deep dive and IBCD Quote: (Originally Posted by Lilou6) For PCDiver, Like we say in france i think you want the butter, the money of the butter and the ass of the cremiere ( i don't know if this is the right word in english) . Lilian LMFAO! have some green. Translated for Lilian. You want your cake and to eat it and the arse of the woman that made the cake too! __________________ CCR/OC Trimix Instructor Trainer CCR Training to Mixed Gas in Switzerland, France, UK & Germany on Megalodon/COPIS-Megalodon/KISS/Sport KISS/Ouroboros/rEvo/Inspiration/Evolution/Sentinel www.zerogravitydiving.com Rebreather World Terms & Conditions
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11th August 2007, 07:30	#18 (permalink)
PCDiver Submerge Productions Current Rebreather/s: Inspiration Vision Other Rebreather/s: Inspiration Classic Join Date: Feb 2005 Location: Belgium Posts: 938	Re: Bailout after deep dive and IBCD Quote: (Originally Posted by Decodiver) LMFAO! have some green. Translated for Lilian. You want your cake and to eat it and the arse of the woman that made the cake too! The of the will be fine ... No cake ... I'm on a diet.
(Online)

11th August 2007, 12:06	#19 (permalink)
Lilou6 New Member Current Rebreather/s: Optima Other Rebreather/s: Not Bought Yet Join Date: Jun 2007 Location: South of the france Posts: 47	Re: Bailout after deep dive and IBCD The woman who make the cake to me have this tool Lilian
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11th August 2007, 19:32	#20 (permalink)
*ScubaDadMiami* Moderator Current Rebreather/s: Optima Other Rebreather/s: Join Date: Sep 2005 Location: Florida, USA Posts: 2,076	Re: Bailout after deep dive and IBCD I currently go with what Dave O suggests. I go on my bottom mix, and then I make a switch to EANx 70. I really don't want to start carrying more than two offboard tanks. I also do not want to have to depend on tanks hung from the boat or line in case I can't get to that location. So, the intermediate mix variation is not for me. BTW, going a a helium mix at a deeper depth (such as 50/25, etc.) works great. It is just a question of the logistics of how much gas you need to carry in each tank for the profile. __________________ Howard Packer IANTD CCR Instructor Miami Beach, Florida CCRDiveTraining.com
(Online)

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