Northwest Dive Club

Well, I thought it would be fun to start a thread about my transition to closed circuit diving. Fun for me, anyway!

I did my first "post class" dive with Ken, Howard, and Jackie last Tuesday. They were all on OC, a mix of doubles and single tank-with large pony bottle configs. These are all dive buddies that I literally trust my life with, mind you, but I was actually kinda nervous, and I found myself wishing Calvin was there to share the anxiety with me. We were doing the good old "boundary line -to- I beams" dive that I bet I've done 100 times or more by now- I remember taking Howard down the boundary line for his first time, less than a year ago, as a matter of fact. As we swam out to the traditional "3rd yellow buoy" on the boundary, we discussed the dive profile. I kind of blurted out that I didn't want to lead, and would be more than happy to follow some one! Anyway, after we did a last minute buddy check, we dropped down into 40 fsw and checked each other out again with OK signals on the bottom.....my HUD had somehow become detached during the descent, and I fumbled around for a few minutes getting it squared away.....after signalling "OK" back to the others, we started to head down the line....but I was really not too OK. My trim was waaaaay off, and I could not, for the life of me, figure out why! I kept swimming in a "head up, feet low" position, and to make matters worse, every time I went to add diluent or 02 to my loop, the controls- 02 add button and automatic Diluent valve- were NOT in the right place....(any Meg diver with any experience to speak of is probably chuckling by now!) So, anyway, after about 20 minutes of feeling like a "special needs" CCR diver, I suddenly realized that I had forgotten to secure my counterlungs to my crotch strap, and they were floating up around my ears like a spinal trauma head brace! ](*,) It only took me a minute to secure them, and from that moment on, it was a whole new world!

We ended up having a great dive- everybody asked me if I was OK more than usual, and I actually appreciated the attention. Jackie's suit had a minor flood in the right arm, and we called the dive early, but still had about 45 -50 minutes of down time. Thanks for a great dive, you all!


On another note- I just prepped my Meg for a possible dive tomorrow (weather depending....it's snowing like crazy here, at the moment!) and I've discovered that I really like doing the pre-dive checklist- I find it very relaxing to go through the checklist item by item, methodically making sure that everything is in place and working properly.

Welcome to a whole new world of diving.

well i can say that after doing a long dive with calvin the week before and this one last week it is going to take a few more dives to get used to certain things. i have the loop flush drill down, now just need to work on the next skill in being a oc buddy to a ccr diver.

Hey! No apologies or self-deprecation necessary! I am loving hearing about your guy's transition to CCR, and I expect many others here are as well. Thanks for telling your story Josh!

Even not being a Meg diver I knew what your problem was before you said it. As you learn more and you dive with other people on different rebreathers, You learn the ins ans outs and common issues with each unit. Forgetting to snap the counterlungs down is a common thing.

Dave

Sounds like you guys had a great dive, sorry I missed it. I probably would've known what was wrong had I been there to see your counterlungs floating up above your head.

it was a great dive - thanks for posting, Josh....and for putting up with me asking you if you were ok every other fin kick or so....
i'm up for a class on how to be a good buddy to a ccr diver....lots of new curves to learn even if i don't own one! (yet?)

jackie

Oh, MAN, I'm really chomping at the bit to get the Meg back in the water- I've had to cancel a few recent dives due to really bad weather and equipment issues; the equipment is squared away, now, I have a fresh bucket of sorb at the ready, and I can't wait to get back out there......

Nailer99 wrote:Oh, MAN, I'm really chomping at the bit to get the Meg back in the water- I've had to cancel a few recent dives due to really bad weather and equipment issues; the equipment is squared away, now, I have a fresh bucket of sorb at the ready, and I can't wait to get back out there......

Hi Josh!!!
Get back in that water! you would really have know about those counterlungs floating if you had the neoprene ones like Calvin! Curt Erik and I are heading to dive the B-29 this week to take HD video and stills!! we can post it here if there is a way to post large files?
have a great x- mas everyone on the board!
mel

I'd love to see some footage of that- I don't know about posting large files and how to do that- the best I've seen is youtube. Have a great trip!

scubagrunt wrote:we can post it here if there is a way to post large files?

how big are the files? i have a lot of room on my site. depending on their size, i can probably host them for a while for folks to see, but it wouldn't be a permanent solution.

Well, here's the latest news:

Helium:

Good.


Nailer:

Very tired.


Will write more about the class later, but, yeah, after many, many, deep air dives, ( >130 fsw) (yeah, I know, I know- save it for another thread),
I have finally tasted the good stuff. And it's pretty great. "The lights came on," "It was like I was looking through a paper towel tube," and all that stuff- it's all true.

Nailer!
You go man!
I'll just enjoy reading about your adventures and stick with my 100 fsw or less dives for now!

Josh--

Congradulations on your CCR Trimix Cert, now you can really get on those deep nasty wrecks.

Thanks for the good time the other night at the off gassing party. Let's see--- off gassing, Nitrogen, Helium and also Scotch!!!!! WoW, that was good stuff.

Hooo yeah......the party.......

So, Helium, Nitrogen, and Scotch = trimix?

Thanks for everything, Curt and Mel- another great class!

](*,)

So, I finally did something I've been meaning to do since I started diving the Meg- during my pre-dive tonight, I assembled the unit and left the scrubber out intentionally. Then I added 02 to the loop and started breathing it, giving myself an intentional CO2 "hit." Within a minute, I felt anxious, and had a strong desire to get off the loop, despite the fact that I was breathing 40% O2. Within 2 minutes, I was hyperventilating, had a rapid pulse, and had a strong feeling of impending doom. There were also some visual disturbances- everything seemed kind of gray- like the color had been leached out of the world, or something.
I got off the loop and started breathing ambient air at approximately 2 minutes- I was a little disoriented- maybe a lot, because I had forgotten about keeping track of the time. It took me about 5 minutes breathing ambient air to feel normal again.

My hope is that this little experiment will help me be able to identify a hypercapnic event in the event one happens to me underwater. The symptoms were extremely powerfull, unlike anything I have ever felt before- I honestly don't know how someone could ignore them- maybe it's different when it happens gradually, as it might in the event of a scrubber "breakthrough?"

Wow, powerful experience. Thanks for sharing.

-Valerie

Dude, scary stuff-how long does it take for the CO2 to completely off-gas from your system?

It's funny, because some of the symptoms you mention are ones I've felt in a very mild way when working really hard (say, swimming against a current) underwater.

dsteding wrote:Dude, scary stuff-how long does it take for the CO2 to completely off-gas from your system?

I don't know, really, but like I said, it took me ~5 minutes to feel more or less normal afterwards- which is more than twice as long as I spent going hypercapnic.

dsteding wrote:It's funny, because some of the symptoms you mention are ones I've felt in a very mild way when working really hard (say, swimming against a current) underwater.

Yeah- I know you can get some CO2 buildup on OC, but man, this was really powerfull- totally unmistakable, and horribly unpleasant. I might mistake symptoms of something else for this, but I will never fail to recognize this for what it is. I am quite curious as to what a gradual buildup of CO2 might feel like, but from what little I know about scrubber materials and behavior, a "small" CO2 breakthrough becomes "large" really quickly, because the CO2 keeps recirculating. Maybe I'll pack the unit with some used scrubber and see what happens sometime. (In the dive locker, of course.)

I think it is good you are doing this. Might wanna check with Lynne to see how much CO2 is too much . . .

dsteding wrote:I think it is good you are doing this. Might wanna check with Lynne to see how much CO2 is too much . . .

Yeah- AFAIK, it's pretty safe.....out of the water, anyway. Worst case scenario is that you lose consciousness and start breathing regular air- maybe crack your skull on the way to the floor. It's not like carbon monoxide, I don't think. A couple of experienced CCR divers mentioned to me that they had tried this. I wouldn't try it within 8 hours of an actual dive, or anything.

Hmmm. Maybe some good experimentation......maybe not. Once I wondered what it would feel like to be shot........you know, just in case I was ever shot.

Seriously though Josh, it sounds like you are really approaching this CCR thing with a realistic view of the possibilities, and wisely you are doing everything you can to prepare for them. Hopefully people can learn from your experiences. Thanks for posting and be careful. And remember, never solo dive in your living room!

If you've ever had the rep from 'Second Chance" ballistic vest come around, he can tell you what it's like. Those guys used to put a phone book under their vest and then take a round in the chest........ That's faith in your product!