RB80 vs Inspiration

Mal Bridgeman · January 17th, 2006, 05:08 PM

I don't know zip about rebreathers but I was interested to read on another thread about some logistical issues with exploration style diving which means a DIR style OC rig would not be adequate or at best impractical for the average diver.

Does the RB80 solve that problem, if not why not?

Very interested to hear views from those who know.

Rgrds
Mal

EDIT When I say "average" I don't mean in performance terms

Little Pete · January 17th, 2006, 07:36 PM

It gives gas extension in the order of 8:1 (i.e Al80 drive tank is the same as 8 OC stages).

For that reason it would mean the gas costs dropped significantly and the reserves might be considered larger. I gather that the reserves are more based around the size of OC bailout you have available (presuming worst case scenario of total RB failure).

Some RB users say the unit is not optimal for ocean diving due to certain characteristics. I don't know enough about RBs to make any judgement there.

However it has the cool green hoses and a very funky space age mouthpiece so it's obviously much cooler to use

iani · January 17th, 2006, 08:18 PM

Quote: (Originally Posted by Little Pete)

I

However it has the cool green hoses and a very funky space age mouthpiece so it's obviously much cooler to use

I'll raise you my cool green hoses and comprehensive HUD

Ian

Mark Chase · January 17th, 2006, 08:21 PM

Pete pretty much summed it up. The RB80 is a semi closed gas extender which will give you a fixed mix all the way down and all the way up so you have to gas switch to decompression gases and deco out like OC. This in its self is not the problem. the problem is the WOB on the unit is renowned as being awful and worse than awful if your anything except horizontal. Very DIR :D

The good news is it saves on gas but the bad news is you still need bailout. That said it will do a two day gig no problem on single fills.

For me the way the unit is reputed to dive is a problem. I have had a play on an EDo4 clone and that was awful and I am told they are better than the RB80??. However the big issue is they haven't got and wont get CE mark because the Work of Breathing (WOB) will never meet European standards. So that leaves the YBOD the Meg and the Oriborous as units that wont invalidate my life insurance.

A DIR diver on this forum described using the RB80 as like sucking treacle through a straw. I didn't think the ED04 was that bad but it is bad.

ATB

Mark Chase

Divingniknaks · January 17th, 2006, 08:39 PM

OK time for my dumb questions then :D

Take the Brittanic expedition then, at least I know soemthing of this having spoken to Barry about it over beer

Assumptions

If you did this on an RB80 then you would still require gas switches for deco on the way up (diff mixes for travel gas on the way down as well presumably). You will have a bottom mix in the RB80 and some bailout gas in stages for if the sh*t hits when at the bottom.

If all the above is correct (please enlighten me if not) then what is the advantage of being on the RB80 in this scenario ? I can't see it. The amount of gas carried seems to be the same (except bottom gas) as OC , but with extra task loading working the RB80 ?

If I've missed something then please feel free to humiliate me :D It happens all the time, I'm used to it.

Yours
Hungry for knowledge in Solihull

Mark Chase · January 17th, 2006, 08:50 PM

Quote: (Originally Posted by Divingniknaks)

OK time for my dumb questions then :D

Take the Brittanic expedition then, at least I know soemthing of this having spoken to Barry about it over beer

Assumptions

If you did this on an RB80 then you would still require gas switches for deco on the way up (diff mixes for travel gas on the way down as well presumably). You will have a bottom mix in the RB80 and some bailout gas in stages for if the sh*t hits when at the bottom.

If all the above is correct (please enlighten me if not) then what is the advantage of being on the RB80 in this scenario ? I can't see it. The amount of gas carried seems to be the same (except bottom gas) as OC , but with extra task loading working the RB80 ?

If I've missed something then please feel free to humiliate me :D It happens all the time, I'm used to it.

Yours
Hungry for knowledge in Solihull

Arguably the advantage would be light weight compact kit. You could do the Britanic on ali 80s and a RB80 and have shead loads of gas incase you got into trouble down there. Wth a teem of suport divers to ferry you gas and staged deco gas switch bottles you could do a dive that would be virtualy impossable on OC.

However IMHO te RB80 is a better tool for long dives rather than specificly deep dives.

ATB

Mark Chase

ATB

Mark Chase

true · January 17th, 2006, 09:35 PM

Mark is correct-- the advantage of the RB80 on a project like the Britannic centers on logistics. There are no dive facilities on Kea, and every bit of helium and oxygen must be shipped in, along with compressors. As a gas extension device, the RB80 would reduce the logistical overhead considerably for bottom gas, travel gas, and deco gas.

(Remember that GUE staged its Britannic dive in 1999, before the RB80 had been developed. The original Halcyon breathers were brought along for the project, but not used because conditions were so bad that it took upwards of a half hour to get divers out of the water and into the boat in regular doubles-- it was a nightmare.)

That said, keep in mind that Halcyon builds the RB80 with a specific purpose in mind-- it is a tool to facilitate exploration diving. It is a specific tool that balances design issues in favor of diver safety. The training requirements alone create a barrier to entry that will keep 99% of the diving community off the unit. Unlike the Inspiration, it will never be marketed toward the general diving population.

I often hear comments repeated by divers who have never been on an RB80 about the work of breathing, but not so much from people who are actually diving the unit as intended. If it is so horrible, why are all of the longest cave records held on the unit? It is the breather at the end of the line in Wakulla, in France, Chip's Hole, and at Cathedral. These guys are doing six hour penetrations in the 200-300 foot range, and then using the RB80 to deco out. I wouldn't imagine it could be possible if the WOB were as bad as the Internet's chattering class makes it out.

anthony

Janos · January 17th, 2006, 09:41 PM

Quote: (Originally Posted by Divingniknaks)

If all the above is correct (please enlighten me if not) then what is the advantage of being on the RB80 in this scenario ? I can't see it. The amount of gas carried seems to be the same (except bottom gas) as OC , but with extra task loading working the RB80 ?

I think that's pretty much it. You could get away with twin 3s and an RB80 instead of twin 18s. But I would choose the twin 18s.

Janos

Mark Chase · January 17th, 2006, 10:09 PM

Quote:

I often hear comments repeated by divers who have never been on an RB80 about the work of breathing, but not so much from people who are actually diving the unit as intended. If it is so horrible, why are all of the longest cave records held on the unit? It is the breather at the end of the line in Wakulla, in France, Chip's Hole, and at Cathedral. These guys are doing six hour penetrations in the 200-300 foot range, and then using the RB80 to deco out. I wouldn't imagine it could be possible if the WOB were as bad as the Internet's chattering class makes it out.

But I have dived an ED04 which has the same bellows design and it is awful. The DIR diver on here had dived the RB80 and he said it was like sucking syrup through a straw.

Also GI3s record dives were not done on an RB80 They used the fridge :D a totaly diferent beast. The MK15.5 CS Luna and now the Oriborous have been involved in longer deeper dives inside caves than some of these.

ATB

Mark Chase

lizardland · January 17th, 2006, 10:25 PM

One certain famously non-DIR UK cave diver probably holds the end of more caves on a KISS in Europe than any other rebreather.

I've used the EDO04, I almost bought one until I tried it and saw people using it. The WOB I found was very poor in comparison with full CC. However it is simple logistics that put me off. And it is certainly not a lightweight rig, it is a very heavy unit and has tremendous drag. The internet chattering classes go on about it being the size of an AL80 which it is until you strap two drive bottles on to it and then it becomes a totally different beast. It is not an easy lump to swim with when it has a pair of 12's or 18's banded on the side. Even getting in/out the water is a challenge.

I dive a KISS. I go caving in France and take a decant bottle of O2 and a decant bottle of mix and a keg of lime and maybe some air to top off with. That does me for a week. With a passive SCR I need to have different drive bottles for different depths/caves and/or do a fair old bit of filling. I can also get my KISS into smaller cave than I could with a passive SCR.

The RB80 is a very well designed RB for the diving it was intended for, which is a narrow mission specific band. It is not an everyday unit. I don't think there is any single RB which is. I really do not see the point in using it in open water, I don't see much logistical advantage in it over open circuit for wreck dives, especially DIR stylie where run times are minimised.

January 17th, 2006, 05:08 PM	#1 (permalink)
Mal Bridgeman (Online) New Member Join Date: Nov 2005 Location: Suffolk, UK Posts: 662	RB80 vs Inspiration I don't know zip about rebreathers but I was interested to read on another thread about some logistical issues with exploration style diving which means a DIR style OC rig would not be adequate or at best impractical for the average diver. Does the RB80 solve that problem, if not why not? Very interested to hear views from those who know. Rgrds Mal EDIT When I say "average" I don't mean in performance terms __________________ Opinions and beliefs are correct at the time of posting but are subject to change without any notice or obligation on the part of the author. Last edited by Mal Bridgeman; January 17th, 2006 at 06:07 PM.

January 17th, 2006, 08:21 PM	#4 (permalink)
Mark Chase(Offline) New Member Join Date: Nov 2005 Location: Kent England Posts: 905	Pete pretty much summed it up. The RB80 is a semi closed gas extender which will give you a fixed mix all the way down and all the way up so you have to gas switch to decompression gases and deco out like OC. This in its self is not the problem. the problem is the WOB on the unit is renowned as being awful and worse than awful if your anything except horizontal. Very DIR :D The good news is it saves on gas but the bad news is you still need bailout. That said it will do a two day gig no problem on single fills. For me the way the unit is reputed to dive is a problem. I have had a play on an EDo4 clone and that was awful and I am told they are better than the RB80??. However the big issue is they haven't got and wont get CE mark because the Work of Breathing (WOB) will never meet European standards. So that leaves the YBOD the Meg and the Oriborous as units that wont invalidate my life insurance. A DIR diver on this forum described using the RB80 as like sucking treacle through a straw. I didn't think the ED04 was that bad but it is bad. ATB Mark Chase __________________ The only DIR Inspiration diver in the village

January 17th, 2006, 08:39 PM	#5 (permalink)
Divingniknaks(Offline) Resident purveyor of shiney kit.... Join Date: Nov 2005 Location: Midlands UK Posts: 1,038	OK time for my dumb questions then :D Take the Brittanic expedition then, at least I know soemthing of this having spoken to Barry about it over beer Assumptions If you did this on an RB80 then you would still require gas switches for deco on the way up (diff mixes for travel gas on the way down as well presumably). You will have a bottom mix in the RB80 and some bailout gas in stages for if the sh*t hits when at the bottom. If all the above is correct (please enlighten me if not) then what is the advantage of being on the RB80 in this scenario ? I can't see it. The amount of gas carried seems to be the same (except bottom gas) as OC , but with extra task loading working the RB80 ? If I've missed something then please feel free to humiliate me :D It happens all the time, I'm used to it. Yours Hungry for knowledge in Solihull __________________ Phill ----------------------------- Salvo Lights, DirZone Gear , Frog Wings Dive ? http://www.divingniknaks.com

January 17th, 2006, 08:50 PM	#6 (permalink)
Mark Chase(Offline) New Member Join Date: Nov 2005 Location: Kent England Posts: 905	Quote: (Originally Posted by Divingniknaks) OK time for my dumb questions then :D Take the Brittanic expedition then, at least I know soemthing of this having spoken to Barry about it over beer Assumptions If you did this on an RB80 then you would still require gas switches for deco on the way up (diff mixes for travel gas on the way down as well presumably). You will have a bottom mix in the RB80 and some bailout gas in stages for if the sht hits when at the bottom. If all the above is correct (please enlighten me if not) then what is the advantage of being on the RB80 in this scenario ? I can't see it. The amount of gas carried seems to be the same (except bottom gas) as OC , but with extra task loading working the RB80 ? If I've missed something then please feel free to humiliate me :D It happens all the time, I'm used to it. Yours Hungry for knowledge in Solihull Arguably the advantage would be light weight compact kit. You could do the Britanic on ali 80s and a RB80 and have shead loads of gas incase you got into trouble down there. Wth a teem of suport divers to ferry you gas and staged deco gas switch bottles you could do a dive that would be virtualy impossable on OC. However IMHO te RB80 is a better tool for long dives rather than specificly deep dives. ATB Mark Chase ATB Mark Chase __________________ The only DIR Inspiration diver in the village*

January 17th, 2006, 09:35 PM	#7 (permalink)
true(Offline) GUE Join Date: Dec 2005 Location: Florida Posts: 141	Mark is correct-- the advantage of the RB80 on a project like the Britannic centers on logistics. There are no dive facilities on Kea, and every bit of helium and oxygen must be shipped in, along with compressors. As a gas extension device, the RB80 would reduce the logistical overhead considerably for bottom gas, travel gas, and deco gas. (Remember that GUE staged its Britannic dive in 1999, before the RB80 had been developed. The original Halcyon breathers were brought along for the project, but not used because conditions were so bad that it took upwards of a half hour to get divers out of the water and into the boat in regular doubles-- it was a nightmare.) That said, keep in mind that Halcyon builds the RB80 with a specific purpose in mind-- it is a tool to facilitate exploration diving. It is a specific tool that balances design issues in favor of diver safety. The training requirements alone create a barrier to entry that will keep 99% of the diving community off the unit. Unlike the Inspiration, it will never be marketed toward the general diving population. I often hear comments repeated by divers who have never been on an RB80 about the work of breathing, but not so much from people who are actually diving the unit as intended. If it is so horrible, why are all of the longest cave records held on the unit? It is the breather at the end of the line in Wakulla, in France, Chip's Hole, and at Cathedral. These guys are doing six hour penetrations in the 200-300 foot range, and then using the RB80 to deco out. I wouldn't imagine it could be possible if the WOB were as bad as the Internet's chattering class makes it out. anthony Last edited by true; January 17th, 2006 at 09:40 PM.

January 17th, 2006, 07:36 PM	#2 (permalink)
Little Pete(Offline) New Member Join Date: Nov 2005 Location: UK Posts: 509	It gives gas extension in the order of 8:1 (i.e Al80 drive tank is the same as 8 OC stages). For that reason it would mean the gas costs dropped significantly and the reserves might be considered larger. I gather that the reserves are more based around the size of OC bailout you have available (presuming worst case scenario of total RB failure). Some RB users say the unit is not optimal for ocean diving due to certain characteristics. I don't know enough about RBs to make any judgement there. However it has the cool green hoses and a very funky space age mouthpiece so it's obviously much cooler to use

January 17th, 2006, 08:18 PM	#3 (permalink)
iani(Offline) New Member Join Date: Nov 2005 Location: Middlesex Posts: 76	Quote: (Originally Posted by Little Pete) I However it has the cool green hoses and a very funky space age mouthpiece so it's obviously much cooler to use I'll raise you my cool green hoses and comprehensive HUD Ian

January 17th, 2006, 09:41 PM	#8 (permalink)
Janos(Offline) "Two Sheds" Join Date: Nov 2005 Location: Surrey Posts: 400	Quote: (Originally Posted by Divingniknaks) If all the above is correct (please enlighten me if not) then what is the advantage of being on the RB80 in this scenario ? I can't see it. The amount of gas carried seems to be the same (except bottom gas) as OC , but with extra task loading working the RB80 ? I think that's pretty much it. You could get away with twin 3s and an RB80 instead of twin 18s. But I would choose the twin 18s. Janos __________________ You can lead a horse to water but you can't climb a ladder with a large bell in both hands - Vic Reeves www.hellfins.com/shed

January 17th, 2006, 10:09 PM	#9 (permalink)
Mark Chase(Offline) New Member Join Date: Nov 2005 Location: Kent England Posts: 905	Quote: I often hear comments repeated by divers who have never been on an RB80 about the work of breathing, but not so much from people who are actually diving the unit as intended. If it is so horrible, why are all of the longest cave records held on the unit? It is the breather at the end of the line in Wakulla, in France, Chip's Hole, and at Cathedral. These guys are doing six hour penetrations in the 200-300 foot range, and then using the RB80 to deco out. I wouldn't imagine it could be possible if the WOB were as bad as the Internet's chattering class makes it out. But I have dived an ED04 which has the same bellows design and it is awful. The DIR diver on here had dived the RB80 and he said it was like sucking syrup through a straw. Also GI3s record dives were not done on an RB80 They used the fridge :D a totaly diferent beast. The MK15.5 CS Luna and now the Oriborous have been involved in longer deeper dives inside caves than some of these. ATB Mark Chase __________________ The only DIR Inspiration diver in the village

January 17th, 2006, 10:25 PM	#10 (permalink)
lizardland (Online) LCS Join Date: Nov 2005 Location: Evidently Chickentown Posts: 593	One certain famously non-DIR UK cave diver probably holds the end of more caves on a KISS in Europe than any other rebreather. I've used the EDO04, I almost bought one until I tried it and saw people using it. The WOB I found was very poor in comparison with full CC. However it is simple logistics that put me off. And it is certainly not a lightweight rig, it is a very heavy unit and has tremendous drag. The internet chattering classes go on about it being the size of an AL80 which it is until you strap two drive bottles on to it and then it becomes a totally different beast. It is not an easy lump to swim with when it has a pair of 12's or 18's banded on the side. Even getting in/out the water is a challenge. I dive a KISS. I go caving in France and take a decant bottle of O2 and a decant bottle of mix and a keg of lime and maybe some air to top off with. That does me for a week. With a passive SCR I need to have different drive bottles for different depths/caves and/or do a fair old bit of filling. I can also get my KISS into smaller cave than I could with a passive SCR. The RB80 is a very well designed RB for the diving it was intended for, which is a narrow mission specific band. It is not an everyday unit. I don't think there is any single RB which is. I really do not see the point in using it in open water, I don't see much logistical advantage in it over open circuit for wreck dives, especially DIR stylie where run times are minimised.