My CCR course - report

[Temple of Doom]

Ah yes, of course. I was thinking that you wouldn't have to worry about the counter-lung, as it essentially nullifies the change in buoyancy from your lungs. Naturally though that volume of air in the lung/counter-lung system would vary.

Though I still suppose that if you get the weighting down right you should rarely need any air in your wings. Is that not so?

Thanks all,

Craig

 

[Gill Envy]

I am weighted so that I leave no air in the wing, that makes changing depths easier to manage. The challenges of buoyancy on a rebreather in cold water is not just a matter of three bladders (W, CL, DS), it's also a matter of the shifting center of gravity as you change positions... Once you get it pegged it's like floating in air, very sublime, with no change upon inhale and exhale, but as soon as you diverge from the horizontal position and air in your suite and CL shifts, then the center of gravity shifts and you all to often end up head up (most common) or head down. To address this, many folks disburse their weights more evenly, not just around their weist. My ankle wieghts ended up best placed behind the counter lungs up near the top of my chest. Buoency is also greatly helped by a square or stair stepped profile which minimizes changes in depth as compared to a steady curve. I used to constantly change depth on OC along a steady curve that was largely dictated by my remaining NDL. Now I have to think ahead and hedge my NDL a bit to better match the appropriate next depth that I want to level out on. It sounds harder than it is but takes time to master before it feels good.

One of the things I love about rebreathers is how much more time I have to make such adjustments. the off gassing and variable NDL's (vastly accellerated continuious decompression upon ascent) of rebreather diving creates a wonderful extension of bottom time once you get the "hang" of it.

Those starting out can expect to put 20-30 hours on their unit before pangs of buyers remorse are gradually replaced by the joy of warm, silent diving, continuious nitrox blending and Loong crittter filled dives.

g

Ah yes, of course. I was thinking that you wouldn't have to worry about the counter-lung, as it essentially nullifies the change in buoyancy from your lungs. Naturally though that volume of air in the lung/counter-lung system would vary.

Though I still suppose that if you get the weighting down right you should rarely need any air in your wings. Is that not so?

Thanks all,

Craig

 

[Temple of Doom]

Those starting out can expect to put 20-30 hours on their unit before pangs of buyers remorse are gradually replaced by the joy of warm, silent diving, continuious nitrox blending and Loong crittter filled dives.

Heh, I can imagine that those pangs would be scary after investing so much. I can also imagine there's a whole lot of denial where you don't want to even think that you may have made a mistake. It's good that it goes away after 20-30 hours (what is that about 15-20 dives!?).

The more I read about CCRs, the more I'm interested. Now that I've been reading around, there's a lot less 'black hoodoo magic' that is pretty much universal in the OC world. I can imagine that in 30 years, CCRs are going to be much more accessible, and divers are going to be looking back and thinking it was madness to dive with OC.

Maybe in a few years, if my buddy and I have the skills, desire, and money, we'll look at taking the plunge. Until then I'll read the exploits with jealousy.

Craig

 

[mania]

hubby has about 15hrs on his unit so far and still working on his bouyancy (playing with weights & counter lungs)

This is reassuring. Becasue I have only 8 hours on my belt
I will keep you posted.
Mania

 

[Gill Envy]

Craig, it's definitely alluring and the CCR world has finally reached critical mass where much more user friendly units are becomming more generally available, there is no waiting 30 years, the time has come. Even still, I don't think CCR's will ever replace OC rigs completely. CCR's are an amazing tool that requires a significant investment in money, training and upkeep, even if the price comes down, the complexity will always be there. They are not for everybody. My wife for instance, on her second rebreather now, is considering giving up RB diving because in cold water it's too much hastle with a dry suite. OC and CCR are just different tools with different capacities. One is not catagorically better than the other, it's all relative to your desires and needs.

Heh, I can imagine that those pangs would be scary after investing so much. I can also imagine there's a whole lot of denial where you don't want to even think that you may have made a mistake. It's good that it goes away after 20-30 hours (what is that about 15-20 dives!?).

The more I read about CCRs, the more I'm interested. Now that I've been reading around, there's a lot less 'black hoodoo magic' that is pretty much universal in the OC world. I can imagine that in 30 years, CCRs are going to be much more accessible, and divers are going to be looking back and thinking it was madness to dive with OC.

Maybe in a few years, if my buddy and I have the skills, desire, and money, we'll look at taking the plunge. Until then I'll read the exploits with jealousy.

Craig

 

[almitywife]

Originally Posted by Gill Envy
Those starting out can expect to put 20-30 hours on their unit before pangs of buyers remorse are gradually replaced by the joy of warm, silent diving, continuious nitrox blending and Loong crittter filled dives.

Im sometimes still have spousal remorse (on the meg-not the hubby) but hubby assures me he is happy with the purchase and eager to learn more & dive it

Mania... any truth to the rumor that you dont feel as cold on CCR as you do on OC??? something about the air is warmer to breath and the oc tanks?

 

[DiveTub]

Mania... any truth to the rumor that you dont feel as cold on CCR as you do on OC??? something about the air is warmer to breath and the oc tanks?

Hi Almity
Indeed it is true, the air in the loop of a CCR runs at between 25-32c, this is due to the chemical reaction in the scrubber that produces among othe things water and heat. Hence you are breathing lovley warm moist air. Next time Theo is diving with you have a scroll through the handset and the computer will show you the internal and external tempratures. Or even better remove the scrubber right after a long dive and hold it in your hands, it feels like you have your own personal heater.

As you know the compressed gas in your tank is filterd to remove as much moisture as possible making the air very dry to breath, along with it being high pressure hence making it very cold as well. I dread having to breath OC in winter and much prefer to stick to the warmth and comfort of the Rebreather.

Cheers
Chris

 

[scubanimal]

Almity,
My wife had no interest in RBs no matter what I said, until she heard 3 lady's come out of the water (low 50's) and loudly proclaim that was first time they've ever been warm diving that time of year, then her interest began. The amount of warmth though does vary amoung the different units. I found the difference on one of my units to be roughly the equivilant of going from a wetsuit to a drysuit in terms of warmth.
However to be fair, now that I'm silent in the water I find I'm staying very still more often while having the critters come to me and such. That then produces cold that I would not otherwise have. But its so cool, I had a bat ray come park itself above me Sat, and a 200 lb black sea bass turn around, come back to me and then just sit and exchange stares till I finally grew bored and left. I don't get those kind of interactions on OC.

 

[mania]

Mania... any truth to the rumor that you dont feel as cold on CCR as you do on OC??? something about the air is warmer to breath and the oc tanks?

Yeap and you know - it really makes a difference. In Poland we mostly dive in cold water. So despite the dry suit I would probably freeze to death on 90 minutes dive. But with CCR I even didn't need to think whether I'm cold or not, becasue I was not.

Mania

 

[almity1]

hubby has about 15hrs on his unit so far and still working on his bouyancy (playing with weights & counter lungs)

This is reassuring. Becasue I have only 8 hours on my belt
I will keep you posted.
Mania

Hi Mania

16 hours in and my issue buoyancy is slowly fading and everything is clicking into place.

My issue wasn't weight or the amont of weight but weight distribution.

I found I had too much weight under the counterlung which caused me to see-saw and when I went too far in a head down position, both gravity and momentum took over and I was face planting.

I put that down to the 3l fabers, during traing (with the Meg) I was using the Ally tanks and having the weight behind the couterlungs was required.

Now I have all my weight in the side weight pouches all up 10 pounds with a Stainless Steel Back Plate.

All I can recommend is the next few dives, just go out there and work on configuration alone, dive for 20 minutes come out make some changes and go back in and do it all again and if you know someone with a video camera or just a Point and Shoot with a big Memeory Card, get them to take a video and play it back and see what you need to do.

Thats what me and my wife did, and I am sure that you will work things out in a scrubber duration, saving heaps of time later.

If you find you need more weight. This may help

http://www.divedesign.be/alibox.html

This also protects the inspo quite well, I friend of mine has one, it makes the Inspo look like a Meg.

Good Luck with it!!!!! Let us know how you get on