[andy2tanx]

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Right, Ive been thinking about this all day, (head hurting, need more beer!) and I have some questions.  These will probably lead on to more questions so please be patient.  Remember, I know sod all about RB's.  so, relating to an Inspiration...

1.  Is diving a box a lot more complicated than OC.  If so, in what way?

2.  What are the costs involved?  I know how much they are to buy, and I know what I need to spend to get trained, but how much is sofnalime, and how long does it last?  

3.  Relating to the above question, what sort of time/costs/jobs  are involved in keeping the box diveable?

4.  What are the benefits to a diver like me, who really spends his time in the 20 - 50 metre region but hates decompressing?

Hope you all don't mind answering these, I just need the info before I sell all my gear and go for it.

tanx

 

[angleseydiver]

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<font color='#000080'>hiya Andy,
   glad to hear you all had a good-un.
I love my box but I'll try to be impartial with my answers to your Qs:

1: No.  .........it seems so for first 10 dives or so but then it's probably simpler. I can sympathise with MC on the kitting-up hassles- I thought "£4000+! can't be doing with this everytime! what the f*ck have I done?" ...So I changed the waist-strap for a yellow one with a S/S buckle and it's now a piece of p*ss. Mind you, Elfyn left all the trendy blacks on his and has no trouble (after 3-yrs  

)
Forgot I had a chest-strap!......still on there somewhere. Added a crotch-strap....can't remember if it made much difference but it's on so I use it.
There were two extra "tubes" of material down inside edges of counterlungs...sewed-up bottom-end, filled with 3lb each of lead-shot, sewed-up top-ends. Makes unit a bit heavier, but 6lb off weight-belt. (need occ. juggling to soften up)
Lung-dump only needed for flushing loop - bouyancy corrections made by releasing gas round mouthpiece/through nose.
Auto-air is clipped loosely in middle velcro hose-strap allowing about 6" of "slack" to play with and will pull out easy if you need it for your gob.
2: Sofna-lime - £ 6.00 or so per fill  :recommended 3 hours- done 4,5 occ.6  

ave. dive 1hr so £ 2.00/dive at worst.
    Batteries -  x2 = £ 4.00 30-ish hrs (if you don't leave your set on, which you will occ) worst case, say 40p/dive.
    Cells x3 = £ 180.00 reckoned to last 18mths,( I've got through 4 in 3yrs) recommended to change every 12mths, ave 100 dives/year?, so £1.80/dive.
     Gas - N/A : got compressor & booster-pump,  we use about 3 J's O2/yr = £60.00 for the two of us.
Had J of He for two yrs- down to 80b, usually put a squirt in for most 40m+ dives.
3: service costs: 2x apex, 1 DIY Auto-air, 1 bail-out reg for the lift-bag/bailout sling.
Time involved : less than chasing around after nitrox fills etc.
Typical weekend- 2 "deepies" + 2 shallow : probably wouldn't open box.
Change lime -10 mins
      "    battery - 5 mins
      "    cell- 15-20 mins
      "    O2/Dil - 2 mins
Set up for dive/checks - 5 mins (usually do pre-dive checks/callibration on land to ensure it will go to dive-mode and do pre-breathing checks. Then strap it on and re-do pre-breath/checks prior to jumping in. ....Remember to switch off in between!)
4 : Benefits are many.
No probs with MODs, changes of site, gas switches, getting right mix, carting extra cyls etc. Cheap trimix when you get that far.
On the downside : it WILL let you down occasionally,
it WILL p*ss you off sometimes with niggly cell-errors (they don't like inversion), the handsets will occasionally switch-off when you jump in -always check them once you've hit the watter. Sometimes it will feel like a wardrobe on your back and you can't take it off to squeeze in like you can with OC.
17 ? people have died on them.
I definately prefer it to OC....I need a dive, it's been a lean year, great weather but little diving, 8mph SW tomorrow..........hmmmmmmm....
ATB,
        Terry

 

[BJ]

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With OC it is important to be able to breathe. You either are or you aren’t. With CCR it is important to know WHAT you are breathing because you can always breathe easily but if the gas is not life-supporting you can....well, you know what I mean.

 

[Rob Evans]

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1. No it's not, it's just different. Wizzing up and down inside wrecks is more of an arse cos exhaling to reduce your bouyancy doesn't work and vice versa. You take it all a bit slower.
2. As per Terry, I tend to go for about 4hrs from a fill of lime. Gas costs are very very small.
3. 3 new cells every year at £55 a piece. Plus maybe a spare.  Batteries cost buttons, but if you've got an older unit costs can start to mount up on replacing the consumables.  Lungs £300. Solenoid £41. Entire b*stard wiring loom cos mine's 6yrs old and the previous owner flooded it - £180 + new handset £160.
4. To be honest, if you're diving 20-50 and are comfortable with 12s and a stage you won't see any difference in terms of deco. The advantages are never having to muck about with nitrox fills, the weight will tend to be less depending on your bailout obviously, fish WILL get closer to you, the gas you breathe is warm and moist and there's a bit less faffing about on the stops changing regs.

Unless you're doing absolute shitloads of 40+ dives it is actually impossible to justify the considerable extra expense (and embuggerance if you want to take it on holiday). Think hard and long. Regardless of gas costs it's a very expensive undertaking in terms of kit, training and ongoing maintenance.  

Got mine so I could pursue the 40-90 stuff and it's absolutely ideal - however it's also lovely for pottering around at 30m.  But then the OC guys on the boat  nick the all post dive biccies  cos average runtime tends to be 90-120min.

 

[Dr Stevil]

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all the guys I know who went from OC to CCR say it's like learning to dive all over again, having tried the BSAC rebreather experience sessions I can see what they mean.
As for post-dive kit care, i've seen one of these guys spend up to three hours after a dive getting the kit cleaned and prepped for the next time, so definately need a bit of patience.

I'm sure one day I'll get one too,  but at the moment I don't think I could find enough time for all the necessaries

 

[peter k]

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Different question but while we're pestering the breather boys for info. I'll ask it.
Why does breathing at a constant ppO2 of 1.6/1.4 build your CNS exposure up to dangerous levels? Or am I missing summat?

Peter

 

[Rob Evans]

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3hrs?

?

 Anal or wot?
One hour at the very most for the big weekly clean, disinfect & scrubber change.  You don't have to completely strip & reassemble the thing to keep it in good order.  If I'm diving all weekend the box stays closed all weekend apart from opening the top hoses at the end of Saturday's dives to get a bit of air to the scubber lid & dry out the condensation.

Peter - I thought this would be in your Nitrox manual mate.
Max exposure @ 1.3 PO2 3hrs
                  @ 1.4 PO2 something something (help me out someone!)
                  @ 1.5 PO2 more of the same (I've got an OW manual around here somewhere...)
                  @ 1.6 PO2 45mins (wahey!)

 

 

 

[MATTBIN]

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Quote[/b] ]Peter - I thought this would be in your Nitrox manual mate.

It is  

Matt

 

[peter k]

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*Flutter, flutter go the pages* Ah right OK, 150mins. I get it now.

Peter

 

[MATTBIN]

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RTFM

Matt