Ice Diving and Cold Water Advice Needed

Marvintpa · 28th February 2008, 13:32

Steve, please keep in mind that the Halcyon boys (*astoundingly* good at what they do) don't necessarily ice dive those units and will be unlikely to speak like they do (at least that was my experience with JJ). So what they tell you for their conditions will be right on the money, but in our conditions you may have a little trial and error factor they can't speak to. I didn't ice dive the RB80, so I can't be of much help, but the recommendations to warm the scrubber before getting in the water are very accurate. You have the benefit of a good canister that is quite large, so insulation will be in your favour once the exothermic reaction starts. You are also getting more fresh gas each breath than CCR guys so it's less of an issue while the scrubber is warming.

se2schul · 28th February 2008, 13:55

Wow, great responses. Thanks again.
I'm really hoping to avoid the trial and error business by tapping some of the cold water experience on this list.

The main reason that I'm being so cautious is that CO2 has me a bit freaked out. During the course, we did a dive without sorb in the cannister to experience hypercapnia. I found the result quite surprising. I didn't suddenly notice symptoms of hypercapnia, instead, it was very subtle. I found that it crept in so slowly that I really didn't notice until it was too late. It wasn't until I heard my Rebreather adding gas on every breath, instead of every few breaths, that I realized that I must have excess CO2. I don't know if this is common or not. Probably once I dive the unit more to know how things "should" be feeling, I'll be more aware when something like excess CO2 buildup happens.

Nice to get 3 local responses from people I know.
Marc, I don't think we've ever met in person, so if you're at the quarry and see a guy with obscenely large tanks on his Rebreather, it's probably me - stop by to say 'hi'.

Steve

se2schul · 9th March 2008, 13:12

Hi guys,

The tips were much appreciated and helped me get several successful dives in our cold winter climate.

If you're interested, here's a video from yesterday's dive. Nothing special, just swimming around, doing some skills, and basically just getting used to the RB80.

YouTube - Practice with the RB80 Rebreather at the Quarry

mbelair · 9th March 2008, 14:11

Quote: (Originally Posted by se2schul)

Hi guys,

The tips were much appreciated and helped me get several successful dives in our cold winter climate.

If you're interested, here's a video from yesterday's dive. Nothing special, just swimming around, doing some skills, and basically just getting used to the RB80.

Very instructive Steve.

At first I didn't understand why you blew so much gas in the shallows and saw you at the end of the video, switching form OC to SCR and understood.

Strange to see the bellows working on the butt shot Blake took of you.

Thanks for sharing.

se2schul · 9th March 2008, 15:21

Ya, all the bubbles were because I did the first 20 feet of the descent on OC. When I got to the plane (at 20 feet) I switched to SCR and stayed that way until the ascent at the end of the dive.

Steve

mbelair · 9th March 2008, 15:49

Quote: (Originally Posted by se2schul)

Ya, all the bubbles were because I did the first 20 feet of the descent on OC. When I got to the plane (at 20 feet) I switched to SCR and stayed that way until the ascent at the end of the dive.

Steve

That makes it look like you have a fart valve

. As long as it is an Halcyon one

Impressive trim and buoyancy control!

Hats Off.

**Dsix36** · 9th March 2008, 16:01

Good job on the dive - trim, bouyancy etc.

Video wasn't bad either. I liked watching the bubbles dissapate against the ice at the end of the dive, pretty cool. Even if you guys are completely f**kin nuts to be in water that cold.

Sutty · 9th March 2008, 17:02

I don't understand the reason for O/C on the descent, having gone to some efforts to warm up the scrubber why leave it to chill again before breathing it on the dive?

se2schul · 9th March 2008, 18:22

Quote: (Originally Posted by Sutty)

I don't understand the reason for O/C on the descent, having gone to some efforts to warm up the scrubber why leave it to chill again before breathing it on the dive?

It's to avoid the PO2 drop in the shallows.
I was diving nitrox in that video, so it's not much of a concern, but if I had a low PO2 trimix, then the drop could put me hypoxic.

I think that dive was my 4th on the RB80 since my course, so I'm still trying to build all the good habits, like descending on OC, etc. I'd like to get a little more knowledge and experience under my belt before I consider deviating from the instructor's recommendations.

Steve

lift bag mcgee · 10th March 2008, 14:27

Awesome video and thanks for sharing. I had the same questions about pre-warming the scrubber and then decending on OC but I see your points and validity in the training methods.

Again, great video and diving.....best of luck...

28th February 2008, 13:32	#11 (permalink)
Marvintpa Bad knees, matching brain Current Rebreather/s: Classic Kiss Other Rebreather/s: Join Date: Mar 2005 Location: Ontario, Canada Posts: 265	Re: Ice Diving and Cold Water Advice Needed Steve, please keep in mind that the Halcyon boys (astoundingly good at what they do) don't necessarily ice dive those units and will be unlikely to speak like they do (at least that was my experience with JJ). So what they tell you for their conditions will be right on the money, but in our conditions you may have a little trial and error factor they can't speak to. I didn't ice dive the RB80, so I can't be of much help, but the recommendations to warm the scrubber before getting in the water are very accurate. You have the benefit of a good canister that is quite large, so insulation will be in your favour once the exothermic reaction starts. You are also getting more fresh gas each breath than CCR guys so it's less of an issue while the scrubber is warming.
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28th February 2008, 13:55	#12 (permalink)
se2schul Custom Title Allowed! Current Rebreather/s: RB80 / Clone Other Rebreather/s: RB80 / Clone Join Date: Oct 2007 Location: Ottawa, Canada Posts: 105	Re: Ice Diving and Cold Water Advice Needed Wow, great responses. Thanks again. I'm really hoping to avoid the trial and error business by tapping some of the cold water experience on this list. The main reason that I'm being so cautious is that CO2 has me a bit freaked out. During the course, we did a dive without sorb in the cannister to experience hypercapnia. I found the result quite surprising. I didn't suddenly notice symptoms of hypercapnia, instead, it was very subtle. I found that it crept in so slowly that I really didn't notice until it was too late. It wasn't until I heard my Rebreather adding gas on every breath, instead of every few breaths, that I realized that I must have excess CO2. I don't know if this is common or not. Probably once I dive the unit more to know how things "should" be feeling, I'll be more aware when something like excess CO2 buildup happens. Nice to get 3 local responses from people I know. Marc, I don't think we've ever met in person, so if you're at the quarry and see a guy with obscenely large tanks on his Rebreather, it's probably me - stop by to say 'hi'. Steve
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9th March 2008, 14:11	#14 (permalink)
mbelair New Member Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Jan 2006 Location: Montreal Posts: 82	Re: Ice Diving and Cold Water Advice Needed Quote: (Originally Posted by se2schul) Hi guys, The tips were much appreciated and helped me get several successful dives in our cold winter climate. If you're interested, here's a video from yesterday's dive. Nothing special, just swimming around, doing some skills, and basically just getting used to the RB80. Very instructive Steve. At first I didn't understand why you blew so much gas in the shallows and saw you at the end of the video, switching form OC to SCR and understood. Strange to see the bellows working on the butt shot Blake took of you. Thanks for sharing. __________________ Marc
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9th March 2008, 15:21	#15 (permalink)
se2schul Custom Title Allowed! Current Rebreather/s: RB80 / Clone Other Rebreather/s: RB80 / Clone Join Date: Oct 2007 Location: Ottawa, Canada Posts: 105	Re: Ice Diving and Cold Water Advice Needed Ya, all the bubbles were because I did the first 20 feet of the descent on OC. When I got to the plane (at 20 feet) I switched to SCR and stayed that way until the ascent at the end of the dive. Steve
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9th March 2008, 15:49	#16 (permalink)
mbelair New Member Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Jan 2006 Location: Montreal Posts: 82	Re: Ice Diving and Cold Water Advice Needed Quote: (Originally Posted by se2schul) Ya, all the bubbles were because I did the first 20 feet of the descent on OC. When I got to the plane (at 20 feet) I switched to SCR and stayed that way until the ascent at the end of the dive. Steve That makes it look like you have a fart valve. As long as it is an Halcyon one Impressive trim and buoyancy control! Hats Off. __________________ Marc
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9th March 2008, 16:01	#17 (permalink)
Dsix36 Going Down? Current Rebreather/s: Optima Other Rebreather/s: Join Date: Aug 2007 Location: Deerfield Beach, Florida Posts: 1,061	Re: Ice Diving and Cold Water Advice Needed Good job on the dive - trim, bouyancy etc. Video wasn't bad either. I liked watching the bubbles dissapate against the ice at the end of the dive, pretty cool. Even if you guys are completely f*kin nuts to be in water that cold. __________________ THE MORE THAT I LEARN, THE MORE THAT I STILL NEED TO LEARN!!!!!!*
(Online)

9th March 2008, 17:02	#18 (permalink)
Sutty Classic Kiss diver Current Rebreather/s: Classic Kiss Other Rebreather/s: Join Date: Jun 2005 Location: Glossop, Derbyshire, UK Posts: 801	Re: Ice Diving and Cold Water Advice Needed I don't understand the reason for O/C on the descent, having gone to some efforts to warm up the scrubber why leave it to chill again before breathing it on the dive? __________________ Never forget that life is a finite resource.
(Online)

9th March 2008, 18:22	#19 (permalink)
se2schul Custom Title Allowed! Current Rebreather/s: RB80 / Clone Other Rebreather/s: RB80 / Clone Join Date: Oct 2007 Location: Ottawa, Canada Posts: 105	Re: Ice Diving and Cold Water Advice Needed Quote: (Originally Posted by Sutty) I don't understand the reason for O/C on the descent, having gone to some efforts to warm up the scrubber why leave it to chill again before breathing it on the dive? It's to avoid the PO2 drop in the shallows. I was diving nitrox in that video, so it's not much of a concern, but if I had a low PO2 trimix, then the drop could put me hypoxic. I think that dive was my 4th on the RB80 since my course, so I'm still trying to build all the good habits, like descending on OC, etc. I'd like to get a little more knowledge and experience under my belt before I consider deviating from the instructor's recommendations. Steve
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10th March 2008, 14:27	#20 (permalink)
lift bag mcgee New Member Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: Aug 2006 Location: Charlotte, NC Posts: 3	Re: Ice Diving and Cold Water Advice Needed Awesome video and thanks for sharing. I had the same questions about pre-warming the scrubber and then decending on OC but I see your points and validity in the training methods. Again, great video and diving.....best of luck...
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