My First Catastrophic Failure

[muddiver]

Your experience is why I carry a pony cylinder that has a completly redundant regulator. It also doubles as an out-of-air resource and make me pretty much self suffecient in case of an emergency.

Otherwise, I agree with the consensius that your other redundant gas supply (i.e. buddy) probably should have been utilized before going to an emergency ascent.

The main point is you made it to safety in a safe manner.

 

[TheScubaBOB]

... the DM's o-ring blew on descent. Actually it blew pretty much as we reached the bottom at around 20m. He calmly turned to his buddy (his wife and also a DM), started breathing off her octo, then proceeded to doff his gear, closed the valve, removed the reg and tried fixing the problem right there. When he realised that it wasn't going to help, he rigged everything up again, appointed a new DM for the dive (his wife) and did a slow ascent to the surface, all the while breathing off his own gear with a gush of bubbles coming from his tank valve.

I would like to know what first stage he has to feel confident removing the reg from the tank underwater.

With a blown o-ring I wouldn't do anything to releive outward air pressure in the first stage just so it wouldn't flood.

Even if he replaced the o-ring successfully underwater once he reconnects the reg to the valve he'll push air through the first stage.

Is the thinking here that getting the first stage underpressure again will push any water out of it? If so how does this effect the Second Stage (I know most of it is wet anyway) and the SPG where the water would end-up. I guess the SPG would be the one that would actually "trap" the water as the second stage would just breath wet for a short bit?

 

[Deefstes]

I would like to know what first stage he has to feel confident removing the reg from the tank underwater.

With a blown o-ring I wouldn't do anything to releive outward air pressure in the first stage just so it wouldn't flood.

Even if he replaced the o-ring successfully underwater once he reconnects the reg to the valve he'll push air through the first stage.

Is the thinking here that getting the first stage underpressure again will push any water out of it? If so how does this effect the Second Stage (I know most of it is wet anyway) and the SPG where the water would end-up. I guess the SPG would be the one that would actually "trap" the water as the second stage would just breath wet for a short bit?

That's a very good point and I did wonder at the time whether one would want to get water in your regulator loop. I just assumed that pushing air through it would flush the water from it but I realise now that water can indeed get trapped (like in the SPG).

I actually do remember that he had a Mares Abyss second stage (don't know exactly which one) but I'm not sure what first stage he had. I can only assume it must have been MR22 or MR42T, not that it really means anything to me.

I'm actually still in occasional contact with him so I'm certainly going to query him about this when I speak to him again.

 

[Rick Murchison]

About o-ring changes underwater...
It can be done; if you plan ahead and carry the correct o-ring for your tank in the dust cover of your reg, and you have a drop-point knife, it's no big deal to switch it out underwater, and the reg will work for a day or so after the flood before the corrosion jams things up (salt water - you may even be able to get away with it in really clean fresh water without a regulator overhaul, but don't count on it).
Last time I did it there was already green crud inside the reg when I got it to the bench the next day.
Make sure you blow all the hoses out with fresh water and then dry 'em with plenty of air before reassembly. If you get salt water in your pressure gauge it'll fail within a year - don't know any way around that one
I can't say what it'd do to an air-integrated computer or to a first stage mounted transmitter as I have no experience flooding those...
Rick

 

[H2Andy]

i would have definitely not opted for the CESA as my first choice

my first choice would have been to hook up with my buddy and for both of us to do a slow, controlled ascent. if at any time i needed gas, my buddy would have provided it to me.

you never know what may come next, and separating yourself from your buddy and shooting up to the surface may open the door to something you're not expecting and which can bite you now that you are alone

i think the first response to anything underwater needs to be: get with your buddy

two heads and two sets of equipment really come in handy during an emergency

 

[Scott L]

I say switch your regulator/cylinder connection to DIN...

 

[Jeff Toorish]

I'm not sure this was actually a CESA.

To the OP, were you breathing from your reg the entire way up? From what you wrote, I understand you to have had a leak, but plenty or air. Even with a catastrophic failure, as you experienced, on descent, you should have had plenty of air for your ascent. You said your tank was still leaking air at the surface, right?

Jeff

 

[drbill]

This happened at 25 fsw. Undoubtedly there was plenty of air to make a safe ascent which I would not call a CESA either. I've had o-rings blow at nearly 100 ft and had plenty of time to make a safe ascent (no deco obligation incurred) without any threat to my safety. Of course I agree with the suggestions to dive with a DIN reg (never had a blown o-ring with mine in all the years I've used it) and carrying a pony bottle (I carry mine at all times even when I'm buddied up).

 

[Rick Murchison]

Controlled Emergency Swimming Ascent... can be anything from an "exhale all the way" OOA situation where the ascent is fairly rapid to a "breathing normally all the way" 30 fpm ascent without a safety stop... or, if you like, you can narrowly define CESA to not include anything but OOA.
I prefer to call any solo ascent where delaying or stopping aren't considered options as a CESA (unless you abandon the "C" and go for an EBA), so I have no heartburn with the OP's definition here.
Rick

 

[Seaduced]

Sorry to take so long to get back to the post. I went to a dive class right after work yesterday.

After reading all the posts so far, maybe there is a disconnect with my understanding of the definition of a CESA. As some have said, I mean a non-buoyant, swimming ascent, at a rate greater than 30 ft/minute. I’m SSI certified, I was taught Emergency Swimming Ascents and Emergency Buoyant Ascents. I assumed a CESA was a refinement of that. My question is, what is a CESA then? Blow and go? Ditch weights? Max effort swim up? The confusion makes a case for standardized terminology across agencies.

A little more info about the conditions, the bottom was at about 40 fsw, virtually unlimited visibility, almost no current and the water temp was 85F. Diving heaven.

I ascended by swimming up a little faster than a normal ascent. I had enough air of the entire ascent, although I anticipated going OOA during the ascent, because I didn’t know how fast it was leaking out. In fact, I inflated my BC at the surface and swam back to the boat still getting air.

The sequence went something like this;
- heard loud ‘pop’ and rush of air
- stopped breathing
- looked up, definitely coming from my gear
- took a couple of cautious breathes expecting to get water or nothing at all, getting air, probably not a hose
- checked spg, needle moving down, near full tank, I didn’t look at specifically what pressure it was though
- checked depth, 25 fsw, very shallow
- These thoughts crossed my mind
- 1) Air share? Not necessary This is easy, at 25 fsw, it was within my experience and comfort to ascend even without air
- 2) Getting all three of us headed back up would take time I wasn’t sure I had
- 3) My DM buddy should safety stop, I won’t be doing that
- This is where I decided to ascend solo
- 4) I should get moving while I have air
- I signaled ‘you two buddy up, I’m ascending, I’m OK’
- She signaled OK and away I went

Talking with my wife later, she didn’t realize I was losing air at that point. She did watch me go to the surface and hand my gear back to the crew, don the gear in the water and descend back to them. I signaled OK, we finished the dive.

I agree in retrospect, my DM buddy didn’t need the safety stop, but we briefed we would avoid rapid depth changes and do an extended safety stop because of his condition. That’s what came to mind, in the heat of the moment.

If the conditions had been more challenging, being deeper, farther from the boat, having bad viz, current or possible entanglements, I probably would have gone to an air share and ascended together.

Once I started the ascent, I really settled down. I started thinking about what came next. Best choice? Hard to say, I thought it was a good one and still do. Thanks for the support and critique.