Diver one of sixteen to die using high-tech gear

[DiverMole]

OK, Inspiration is good but not perfect in standard form.

Bare in mind that this is my view and others will feel differently. I've just done a big Inspiration owners survey and most have left their unit standard

Mine is an older unit so I have changed quite a fe wthings

I fitted SS backplate and larger wings with a normal harness. I dont have the little lung hold down straps any more so I know they are not important

I fitted an ADV and an Auto dump, so I have fully automated descent and ascent. No task loding at all (now why cant we have ADV's for drysuits!!!)

I fitted a combined OC and CC mouthpiece, for ease of loop closure and bail out

I have larger 7L cylinders for deeper diving and more baiout. The Dil is connected to my OC/DSV and the O2 have a DV on it for deco. So no need to carry side slungs for 70m dives

I have a VR3 fitted with a 4th O2 cell for deco and backup

I have a Hammerhead replacement head as I consider the extra functions and safety features worth while

You can see all my modification on my Inspiration site

On the original unit there is nothing unsafe as such. It all works and is a fine unit for Air diving to 45m or so out of the box. When you start to go deeper and use mix then you probably want to change things to make this easier. The Auto air is a normal first mod. Works well for your bailout but you cant share with it, so most folks fit a long hose DV

Its the same as OC. I bet you have changed stuff on your kit since you first bought it, move stuff, tagges and extra bit or bungie on here and there etc. Is anyone ever truley happy with their dive kit, theres always something that could be better

[FMT]

Divermole, you have a freshness and openness toward talking about the unit (hehe he said unit..) without getting defensive. I can really appreciate that.
I am curious (as DRE is) about dive planning/gas management/bailout proceedures with the unit. To add to that I am curious about how diving with the unit affects team based diving or if this is considered to be pretty much a solo unit. As for me, I am always striving to be a better diver and part of that is taking a critical look at my kit and improving it as I learn and grow.
T

[DiverMole]

OK, lets look at 50-70m dives on OC V Turtle

OC we are talking twin 12's and 232 bar. £35 ($50) for a fill of say 18/30. Also need side slung, say 7l of 50% min, probably 36% and 50%, or 28% and 100% depending on your preferances

My turtle rig for deeper dives has 2 x 7l cylinders, left is 18/30 right 100%. Costs me £10 ($15) for a fill which will last for 4 or 5 50M + dives
The 18/30 ius rigged in to my OC/DSV so I can bail to it istantly and I have a DV connected to the O2.

If I have a problem I bail (if I cant fix it staying on the loop) OC to the 7L of 18/30 (or 10/50) which is plenty to get me to 6m with my now extended stops (I carry an emergency bail out OC table as well as the VR3 being able to do this on the fly). At 6m I go to the O2 DV and can spend up to an hour on 100% (air breaks!!!)

The folks I dive with all tend to carry their own bailout so sharing isn't a problem, but all our dil cylinders (internal or side slung) are fitted with extra whips so we can cross plug our gasses into everyone elses units. I do not dive the unit solo

So lots of options, all safe, all redundant, no need to panic. And this is if you have to come off the loop in the first place (rare). This is why many RB divers believe they are actually safer at depth than the OC guys, we have more ways open to us of getting a breathable gas

If I want to go deeper I just add 7l Ali side slungs with say 10/50 and plug them in as needed

Hope that helps

[spearit]

Oh, the whole truth, and nothing but the ugly truth…

So let me understand here, DRE, you asked “George if I could use his article and he was fine with that.” So, you don’t know what you’re talking about from personal experience, but wanted to bubble an opinion yet originally state it as if it was your words without experience DIVING or trying out CCR units themselves? With the reasoned claim of “I don't have to be a rebreather diver to form an opinion about them - I don't even need to know per se all the technical details involved with the unit (although I did do my homework) to know that they're extremely dangerous to use”… how is it you KNOW they are more dangerous??

Anything more complicated doesn’t mean more dangerous, isn’t it down to the end-user? Should we all put away our OC gear in favor of snorkeling as snorkeling is less complicated and has less risk? And how would I KNOW that, because I have personal experience and training in both. For example: I’ve heard that racecars are more dangerous and more complicated than regular passenger cars, but I don’t KNOW that they are. So when I look at the statistics, so many more injuries are involved with passenger cars every day than racecars. Racecar drivers seemed to be better skilled, have more of an experienced knowledge base on driving, and are better at task loading than the average commuter - and the statistics prove that there are less skilled, less educated, less safe drivers out there in “normal” cars than racecars - but it’s the big crashes on TV that make it seem more risky for the racers.

This is all an analogy alluding to the opinions expressed from those who simply don’t KNOW about what you are talking about when it comes to the Inspiration. - To borrow someone else’s words as your own and then admit to doing so only after someone points it out seems a little unfortunate.
Careful with what you type, you don’t want to lose your credibility, do you? Stick with what you DO KNOW, don't seem to ‘act’ (in approach and wording) as if you are an authority in many of these advanced diver threads.) - Think about all those who are following the forum here and how they can REALLY learn some GREAT insight and expand their future diving, not just feed someone’s desire for God complex.

I suggest those in the forum, not to go around making statements that seem as if they were truth, that they don't have to PERSONAL experience with just to form an opinion it – to know some of the technical details involved doesn’t mean you ‘KNOW’ anything. The example that the Inspiration HAS changed is a big clue to this. As I see many of the opinions formed based of things from the past and not a working knowledge of what refinements, improvements, and adjustments have been made.

Let us not all go on forums saying, “THE SKY IS FALLING” without knowing the CURRENTS facts. Reasoned arguments and developing true knowledge development happens when we ASK questions, not as we STATE what we think we know as truth.

DRE, just because you “approached CERTAIN rebreather divers… they got so defensive no reasoned arguments either pro or con followed” doesn’t warrant you speaking as if you know what you are talking about against RB’s without the experience or having looked further for more open-minded and open-attitude rebreather divers who could inform you properly. Don’t fall back into a pitfall or superiority complex with rebuttals such as, “I thought it was interesting you brought up the fact that in your diving you've come at a point that CCR's are THE ONLY WAY TO GO in terms of gas management.” I don’t believe any of the responses you’ve received said anything about the terms of ONLY way to do anything.

This forum is better characterized without comments of ONLY ways to do ANYTHING, and instead leaving your question that what you asked in, “If you wouldn't mind sharing some of the details of those dives and how you calculate them in terms of gas management that would be very informative.”

This is not to try and create a situation where DRE or anyone else should be on the defensive. Forums are the free exchange of ideas an opinions, but they all end being the same crap on so many others where a few people decide to take over arguments until it is found that one person backs down.

And by the way, I LOVE my snorkel, I get to see more of the underwater world at the surface unlike those who are floating on their backs LOL Just trying to lightening the mood after my little gurggle on how I think things should be
Of course, ALL of this is just my OPINION, it’s not like I KNOW anything ;D

[Groovekitty]

Divermole,

Relative to bailout situations - the only thing that scares me about any closed circut rebreather is the possibility of malfunction. What do you do if the alarm doesn't sound, or you don't hear it, or your buddy doesn't hear it, or whatever and your kit delivers you a toxic hit of O2?

I know you can plan for other types of malfuctions and try to anticipate problems in general with all types of diving, but what is your personal opinion or rationale for a scenario such as this? Do you think of this as a calculated risk or as a risk inherent to CCR units?

Personally, I don't see any rationale for using a device that has the potential to kill you. Now, I know all diving is dangerous, and potentiall hazardous, but what I am getting at is trusting your life to a device that you really have no control over.

I am very interested to see how the mind of a CCR diver works for this very reason.

Best,
~groovekitty*

[Groovekitty]

Spearit,

Do you have any usefull CCR infomation to offer this forum, or do you just enjoy bashing others who are trying to have a critical discussion?

I disagree with you that one must have CCR experience to form an opinion. I can tell you that skydiving is dangerous having never done it and I think you would be pretty hard-pressed to disagree.

If you have information to go along with your opinion, great! Please share it - but keep the chastising to yourself. Just MY opinion.

[DiverMole]

Ah, but there in lies the rub. I have very good control over my rebreather and can tell if it is malfunctioning. I have been trained to spot the problems and trained and drilled hard to be able to respond and fix them

a) I prepared it to my own standards and checked that preparation fully with predive checks and pre-breath

b) I have 4 independant O2 cells in the loop, any one of which I can use to tell the current PPO2. I calibrated all 4 of them just before the dives while watching the calibration coefficients so I can tell if the calibration is good. In fact the 4 cells use 2 independent calibration routines to derive their values (Inspirations own and VR3's) so I can tell if I miscalibrated either by comparison

c) I have all 4 PPO2 readouts available to me at all times during the dive on my handsets. I can look and check all 4 independantly at any time. I can also take steps to verify the accuracy and response of the cells at any time (Dil flush, O2 Flush)

These 4 readouts use 3 independant batteries

d) I also have a HUD (Heads up display) visible at all time with system status relayed in it

e) I have 2 independant handsets also monitoring the dive. One of which can also control the O2 if I fail to do so. The second is monitoring the first and will take over instantly if there is a problem

f) I also have a VR3 which also is monitoring my PPO2

g) I have a buddy also monitoring me and my unit

h) On top of the handsets, rebreather operators have a unique safety device lost on OC folks, it is called hearing. You can hear the smallest air leak and also when the solenoid fires. You soon learn the normal pattern of solenoid firing for you and would be instantly aware if it sped up or slowed down. Until you try it you wont believe how quiet a RB is

I) I can fly the unit manually if I have even one PPO2 readout left

J) I can go semi closed and get a 5X gas duration extension even if I loose ALL PPO2 monitors

K) If all hell breaks loose I can go OC, and then I'm in the same boat as you lot

Basically. I fly my unit, with 3 computers watching over me in case I cock up!! (likely to happen at some time). I have more options open to me if a problem arises.

Also apart from a stuck open solenoid (instantly noticable) all problems on a RB happen slowly. If I turn off my O2 at 50M for example it takes nearly 4 mins for my O2 to drop from the 1.3 bar I run at to .4 bar when all the alarms sounds (still miles from a problem). As I check my handsets about once a min I would have noticed 3 times in that space and the computers would be a final check. My HUD would start flashing amber then red (visible to buddies) well before this (10% devaition set)

The chances of me, 3 computers or 4 cells all going belly up at the same time are less likely than both the regs failing on your twin set at the same time, or a manifold O ring going

You and your buddy will hear the Inspiration buzzer!!!! it's bloody deafening!!!!. My current Hammerhead controller doesn't have an audible alarm, but actually a vibration alarm on my mouthpiece (part of the HUD)

So I'm not worried personally about the risk. It is all under my control completely. I'm a pretty cautious guy and would not use the RB if I thought I was going to die on it. I am convinced personally that if used properly they are safer than OC. I also believe that in 10 years time they will the the normal way of diving. They offer so many benifits over OC it is hard to consider going back

[DRE]

Divermole,

thanks for the gas management scenario. Personally I dive twin 18L, with AL40cf deco bottles. It seems to me your group has figured out ways to deal with gas loss scenarios and still being able to complete the deco safely.
How do you calculate your gas consumption? Personally I always plan for the worse that can go wrong and give myself a saftey margin in terms of gas I carry with me. So do you guys calculate your worst case scenario based upon complete OC bailout or not? For the entire team or not?
Question: do you do any extended overhead environment diving and if so, do you change any of your gas management practices?

[DiverMole]

We calculate our OC bailout in eaxcatly the same way as you do. Assume a high panicky SAC, allow 1/3 for reserve, add a few more stops etc

We assume we will need to bail at the very end of our bottom time and our deco will rise as on OC you are never going to be breathing the best gas on the way up

Normally my group all carry their own bailout gas. We can share each others if we need but dont plan on this

If we go deeper and the amount of OC to carry for Bailout increases we may swap to Tom Mounts method of carrying enough bailout for 1.5 people per the whole team, but personally would prefer to be carrying everything I need myself

There are a group of RB divers who we call "Alpinists", They believe in there own ability to check and fix any problems on the unit and down carry any bailout. ie they do 100m on the 2 inbuilt 3L tanks!!!!, as you've seen from my previous posts, OC bailout is a very last resort. Personally I think this is a very stupid idea, but about 20% of folks do it

[DRE]

That's comforting to hear.
What do you guys use to calculate deco - do you use constant ppO2 deco tables or do you fudge factor with normal tables. Also, could you present a deco schedule for let's say 200ft for 20min so we can compare it to OC?