Reconsidering Deep Air?

[helodriver87]

Three of those fatalities have been discussed here on these forums. The fourth one was an international incident that never made it on scubaboard. I do not know the units and the circumstances at the top of my head but we can browse through fatalities on scubaboard and those that could be attributed to deep air are less than those that can be attributed to CCR. Since there is more money to be made by the latter, weight of political correctness is also behind CCRs at this time.

I don't know that that's a direct comparison. When you have a fatality on CCR, you can typically (but not always, only if it's recovered) look at the unit and dive log to get some data on what may have happened. There's more hard data to work with and it's easier to determine contributing factors when that's available. If the loop went hyperoxic, you can see that on the log. If O2 was depleted or shut off, you can typically identify that. It's much harder to definitively say that the effects of narcosis and gas density were at fault. You can only speculate since there's no hard data available on how impaired someone was and how much it impacted their decisions and outcomes. There's also a tendency for CCR fatalities to get analyzed more heavily by the community. I would hypothesize that cognitive impairment is a factor in quite a few fatalities, but that's harder to prove than recorded PO2 data or an empty O2 cylinder.

 

[Wibble]

I don't know that that's a direct comparison. When you have a fatality on CCR, you can typically (but not always, only if it's recovered) look at the unit and dive log to get some data on what may have happened. There's more hard data to work with and it's easier to determine contributing factors when that's available. If the loop went hyperoxic, you can see that on the log. If O2 was depleted or shut off, you can typically identify that. It's much harder to definitively say that the effects of narcosis and gas density were at fault. You can only speculate since there's no hard data available on how impaired someone was and how much it impacted their decisions and outcomes. There's also a tendency for CCR fatalities to get analyzed more heavily by the community. I would hypothesize that cognitive impairment is a factor in quite a few fatalities, but that's harder to prove than recorded PO2 data or an empty O2 cylinder.

You can't measure how distracted a diver was, only the result.

Relying on the automatic response of the unit makes one lazy. The day that cars become almost autonomous will result in endless deaths with manufacturers tritely saying "there is a clear warning on page 39764 of the manual saying that you must always be ready to take over from the computer at no notice. Most of us will be asleep, doing our expenses or taking selfies and not notice the piano in the middle of the road.

 

[KenGordon]

Bah. I was trying to quote the $20 to $30k assertion about the cost of a rebreather and training.

I paid £8k for a brand new JJ. In USD that would be about $12k. The training costs about £800 per course. So another £2400 or maybe $3600.

Total of about $15k.

Two of the courses I did on holidays, the first in the Red Sea where my GF was OC on most of the training dives, and the last in Shetland diving the deeper wrecks. Those were just diving holidays I would have done, or the equivalent, whether I was on a course or not.

I have bought one extra bailout cylinder above what I had for OC deco diving. I picked up an extra pair of dil/O2 cylinders for flexibility.

I default to getting trimix fills, where available, unless I am pretty certain I will be doing shallow dives as it only saves maybe £10 a fill.

I find I notice being narked with air at significant depth and try to avoid it.

 

[Wibble]

Bah. I was trying to quote the $20 to $30k assertion about the cost of a rebreather and training.

I paid £8k for a brand new JJ. In USD that would be about $12k. The training costs about £800 per course. So another £2400 or maybe $3600.

Total of about $15k.

Two of the courses I did on holidays, the first in the Red Sea where my GF was OC on most of the training dives, and the last in Shetland diving the deeper wrecks. Those were just diving holidays I would have done, or the equivalent, whether I was on a course or not.

I have bought one extra bailout cylinder above what I had for OC deco diving. I picked up an extra pair of dil/O2 cylinders for flexibility.

I default to getting trimix fills, where available, unless I am pretty certain I will be doing shallow dives as it only saves maybe £10 a fill.

I find I notice being narked with air at significant depth and try to avoid it.

Also need to add the extras: spare cylinders, spares, additional coaching, the MOD2, spare bailout cylinders with different gasses, tubs of lime in bulk...

And not forgetting the costs diving your backside off once you've got one! -- yay \o/

 

[jlcnuke]

Bah. I was trying to quote the $20 to $30k assertion about the cost of a rebreather and training.

I paid £8k for a brand new JJ. In USD that would be about $12k. The training costs about £800 per course. So another £2400 or maybe $3600.

Total of about $15k.

Two of the courses I did on holidays, the first in the Red Sea where my GF was OC on most of the training dives, and the last in Shetland diving the deeper wrecks. Those were just diving holidays I would have done, or the equivalent, whether I was on a course or not.

I have bought one extra bailout cylinder above what I had for OC deco diving. I picked up an extra pair of dil/O2 cylinders for flexibility.

I default to getting trimix fills, where available, unless I am pretty certain I will be doing shallow dives as it only saves maybe £10 a fill.

I find I notice being narked with air at significant depth and try to avoid it.

The $20-30k was an estimate based on around the same price for initially buying the rebreather ($12k including all the tanks etc.), plus courses to get to the equivalent of TDI OC trimix (200' training), which if done sequentially I saw courses for that totaling around $4-7k (baseline from places that show prices such as DGX with $2k for the CCR sport diver, $2.5k to get deco after that, and probably another $2.5k to get the deeper 60m deco cert). Then, since I wouldn't be doing the training locally most likely, I'd have to add on hotel and gas costs for the travel ($125+/night with probably 10-12 days of that, plus ~$150-200 in gas costs) which would be another $1.5-2k. Then there's consumables for the courses, spares, etc. For all that it seems like a baseline of $20k would be around the minimum costs for someone to get to that point, more if you were willing to.

Now sure, you could also go the "buy a used rebreather, find the cheapest instruction available, and sleep in your car route and probably get the costs cut in half, but I think most people don't choose that method.

Either way, I was mostly pointing out that rebreather training isn't cheap and thus isn't a cost effective option for lots of people, especially if they aren't routinely doing dives that benefit or require mixed gas.

 

[Wibble]

You can go CCR for considerably less than that. An old Inspiration for $3000; a BSAC rebreather course for a couple or few hundred. Scrimp and scrape on the optional extras. Probably under $5k all in.

OC's not that cheap if you're looking at tech diving. Twinset(s), stages, courses, gas. Lots of gas. Deep devils gas costs lots and it's every dive. 60m dives would be $100+ for gas fills, compared with $10 for CCR.

However, diving isn't cheap. It's a lot like owning a motorbike. A large capital cost for the kit plus "courses" (the metaphor breaks down here...), but thereafter it's relatively cheap, just the cost of paying for the boat ($100?) and taking the day off work ($$$$).

 

[Edward3c]

You can go CCR for considerably less than that. An old Inspiration for $3000; a BSAC rebreather course for a couple or few hundred. Scrimp and scrape on the optional extras. Probably under $5k all in.

OC's not that cheap if you're looking at tech diving. Twinset(s), stages, courses, gas. Lots of gas. Deep devils gas costs lots and it's every dive. 60m dives would be $100+ for gas fills, compared with $10 for CCR.

However, diving isn't cheap. It's a lot like owning a motorbike. A large capital cost for the kit plus "courses" (the metaphor breaks down here...), but thereafter it's relatively cheap, just the cost of paying for the boat ($100?) and taking the day off work ($$$$).

Don't forget you can 'borrow' one of the CCRs managed by BSAC HQ to do the BSAC course

 

[Celt]

Before I’d pay that kind of money for a rebreather, I’d get into the shower and start tearing up 50 euro notes in order to get a feeling for what it’s like.

 

[helodriver87]

You can't measure how distracted a diver was, only the result.

Relying on the automatic response of the unit makes one lazy. The day that cars become almost autonomous will result in endless deaths with manufacturers tritely saying "there is a clear warning on page 39764 of the manual saying that you must always be ready to take over from the computer at no notice. Most of us will be asleep, doing our expenses or taking selfies and not notice the piano in the middle of the road.

That's a fair point, but you can say the same for OC with regards to distraction. My issue with the original statement is that CCR fatalities receive more analysis and there's more focus on the unit and operator/unit interaction. It's easier to make a determination of casual factors in a lot of cases. Distracted diver, malfunctioning unit, etc, if the loop went hypoxic, we can make at least a partial determination of cause. You can really only speculate if narcosis played a meaningful role.

 

[helodriver87]

Cave diver drunk is also accurate.