First stage failures
#1
Posted 28 September 2008 - 03:45 PM
The situation: On the first day of diving, I hooked up to a tank that had a small, sharp edge that I did not see upon visual inspection. When I charged, the seal blew and everybody figured it was the Oring, which someone else changed out and hooked my gear back up to that tank. I did the dive without incident. It was after the dive, when I was switching to the second tank that we found the sharp edge. For the next 2 days, sometimes my first stage would seal without a problem (and maintained the seal throughout the dive), and sometimes it blew on the boat. One time, I got all the way into the water before it blew. The boat had a spare setup on board, they put my computer on that gear and I used it the rest of the trip. It appears that the tank with the sharp edge took a small shaving off my first stage when it blew. Fortunately, my LDS can replace that part without me having to buy a new first stage.
In hindsight, I think I was pretty lucky that the times the seal held up and I took the (unrealized) damaged gear to depth for an hour at a time. I could have easily lost the seal at the first stage at any time.
My first lesson learned is to not rely just upon a visual inspection of any tank I am hooking up to. From now on, I will feel around the Oring to make sure there are no sharp edges.
My second lesson learned is if I blow an Oring, to visually & physically inspect my first stage carefully to ensure that there was no damage to my gear when the Oring blows. And, if there is any damage, not to dive with that gear until an expert checks it out!
My final lesson is one I want your expert help with. "What if" you do lose your first stage seal while below the surface? I know what's briefly taught in OW training, but what should you REALLY do if your first stage blows underwater? Is the answer different depending upon you depth at the time?
I know that there are SD'ers out there who have experienced this, and those who teach what to do. Please post, so we can learn from you!
#2
Posted 28 September 2008 - 04:15 PM
My final lesson is one I want your expert help with. "What if" you do lose your first stage seal while below the surface? I know what's briefly taught in OW training, but what should you REALLY do if your first stage blows underwater? Is the answer different depending upon you depth at the time?
I know that there are SD'ers out there who have experienced this, and those who teach what to do. Please post, so we can learn from you!
If my first stage failed, I'd breathe off it if I could, signal OOA to my buddy, get on his/her reg, shut my tank off, and do a normal ascent. This should be nothing more than an inconvenience. I know many recreational divers eschew the "long hose" or deem it technical gear. I did a little experiment with a newish OW diver that I am mentoring. After a pool session, when I was running quite low on air n my tank, I had some cleanup tasks to perform in the pool. So I asked her to share air with me, while I scooped leaves off the bottom of the 10ft pool into a new and brought them to the surface.
It was a crucial lesson for her to see the difficulty in managing ascents, descents, and general work underwater with a very calm, and well skilled diver. Maneuvering with the standard length octo hose was awkward at best. She now understand why a long hose adds so much comfort to a dive when things go bad.
So, I would suggest you practice your ascents with your buddy while sharing air. And if you can, get to the point where you can share one second stage for an ascent and safety stop. When that becomes trivial, you'll no longer fear losing a first stage underwater.
#3
Posted 28 September 2008 - 05:30 PM
If I had the o-ring go at any depth, I think I would NOT shut off the air. If I shut off the air, then water would definitely run INSIDE my first stage regulator. Surely, get with my buddy (insta-buddy usually) use his spare second stage and abort the dive. Hopefully the insides of the first stage would be kept dry.
What do the "more tec" divers think ?
I would like to add this very similar question; what would we do if the burst disk went while at depth?
#4
Posted 28 September 2008 - 05:40 PM
So, I would suggest you practice your ascents with your buddy while sharing air. And if you can, get to the point where you can share one second stage for an ascent and safety stop. When that becomes trivial, you'll no longer fear losing a first stage underwater.
OK, sounds like what they teach in class is valid, and logical to me. I can see practicing sharing air if you have the same buddy all the time, as I used to. The majority of single divers on this site have different buddies on each SD trip, or each day trip boat for that matter. I cannot see everyone willing to do these practice skills on the first dive done with each new dive buddy. Is discussing sharing air situations sufficient?
The air sharing done during OW class was done on short hose, and yes you do get up close & personal with the one you share air with. Not a problem as I see it, as your main concern is air, not whether you're invading someone's personal space. Of course, as you were working I see the benefit of a longer hose! Impossible to do on a short one.
#5
Posted 28 September 2008 - 05:48 PM
1. Landlocked asked what would happen if you lost the first stage. Not an o-ring. Would your response be the same in both cases?
2. Why would shutting off the tank have any negative bearing on outcome? If you do a normal ascent from any real depth on an AL80, it's going to run dry before you exit the water anyway. Thus necessitating not only a first stage rebuild, but a tank tumble and VIP.
3. Have you ever been in this scenario? The bubble shower is loud, confusing, and a menace. Shutting the air down restores some normalcy to the scenario, and may in fact let you resolve the problem and continue the dive. Admittedly this is a technical bias since we can't simply surface when things go wrong, and we must fix our issues on the water, but surely things that remove confusion and perhaps panic are welcome when dealing with gas loss. Right?
4. Your burst disk question is similar, and I would respond in exactly the same way and for the same reasons. I have a photo somewhere of a divers burst disk going in the cavern at Jackson Blue. The bubble shower is amazing!
#6
Posted 28 September 2008 - 07:18 PM
I have three dive trips to Mexico coming up in the next 2 months, I definately will check.
Thanks, ~ Damselfish
#7
Posted 28 September 2008 - 08:00 PM
I second Perrone's suggestion - "If my first stage failed, I'd breathe off it if I could, signal OOA to my buddy, get on his/her reg, shut my tank off, and do a normal ascent.""What if" you do lose your first stage seal while below the surface? I know what's briefly taught in OW training, but what should you REALLY do if your first stage blows underwater?
This statement bothers me a little bit. Why wouldn't people be willing to do a quick air-sharing practice at the start of any dive with a new buddy? That seems like an incredibly prudent and safe thing to do, and I cannot imagine someone refusing to do it if asked. Actually, if they did refuse, then I think I would immediately start looking for another buddy.I cannot see everyone willing to do these practice skills on the first dive done with each new dive buddy. Is discussing sharing air situations sufficient?
I know how a lot of people feel about DIR, but one of the things that we learn as part of our DIR training is to do an S-drill (or "Safety drill") at the start of each dive, and especially when diving with a new buddy. The steps for an S-drill are:
- One diver signals OOA
- Their buddy donates their backup
- The team gets in an air-sharing configuration
- They swim a short distance
- The skill is repeated with the roles reversed
Regulator failures are uncommon, but not unheard of. That is why air sharing is taught at all levels of training, starting with the OW course. Why does it seem that so many divers feel like they don't need to practice these skills regularly?
-JimG
#8
Posted 28 September 2008 - 08:08 PM
#9
Posted 28 September 2008 - 08:17 PM
Regulator failures are uncommon, but not unheard of. That is why air sharing is taught at all levels of training, starting with the OW course. Why does it seem that so many divers feel like they don't need to practice these skills regularly?
-JimG
Because we only pay lip-service to safety. We don't practice life saving skills. We don't test our regs, we don't test breathe before we hit the water, we don't question our buddies or their practices. We ignore safety briefings on the boat.
We refuse to do anything that might use up our precious air for our dives. Even in the name of safety. This mentality has been creeping into the cave and technical, areas as well. Carrying minimum backup gas. Pushing limits, and failure to adhere to time tested standards.
I backed out of diving because what I saw scared me greatly. And I am now going to be incredibly picky who I choose to enter the water with.
Sorry, but this is hitting VERY close to home for me right now.
#10
Posted 28 September 2008 - 08:52 PM
I backed out of diving because what I saw scared me greatly. And I am now going to be incredibly picky who I choose to enter the water with.
Please give me another chance. I promise to do better next time.
"For the diligent diver, closed circuit rebreathers are actually safer than open circuit scuba." Tom Mount
#11
Posted 28 September 2008 - 09:02 PM
I backed out of diving because what I saw scared me greatly. And I am now going to be incredibly picky who I choose to enter the water with.
Please give me another chance. I promise to do better next time.
My most recent dive with you was served as an example of how things SHOULD go.
Clearly there are different standards when diving in mixed teams. However it becomes even MORE critical for the OW diver to do a self-check on all their breathing gear and safety gear. If that CCR diver has to come off the loop, you essentially have two solo divers i the water and self-rescue is the order of the day.
#12
Posted 28 September 2008 - 09:22 PM
Wow I wouldn't have thought to feel for sharp edges. I 've only just checked for the o ring. I bought my own equipment so that I don't have to worry too much about faulty equipment and if they are inspected and kept up correctly.
I have three dive trips to Mexico coming up in the next 2 months, I definately will check.
Thanks, ~ Damselfish
I have everything but tanks, because I have to travel to dive. I also take very good care of the gear I bought 2 years ago when I certified, but hope this thread lets others know to check the tank valve before hooking up to it, and to make sure before every hookup that your own first stage was not damaged during the previous hookup.
Although I knew theoretically what I should do if it blew underwater, it probably would have scared the hell out of me at first, with all the noise & bubbles, and then hopefully logic, wisdom and determination would have kicked in! I'm also pretty sure that everyone else in the water would have seen/heard the problem and been willing to help.
Perrone, although I suspect you may be right in that the majority of casual divers are of the "lip service to safety" variety, I think we have a better class of diver than "casual" on this board. I for one always listen to the dive leader, test breathe my reg before getting in the water, test my inflator valve, confirm computer battery status, and confirm the setup of gear my dive buddy has. And if hand signals don't work underwater, I'll pull out my small slate and draw pictures if I have to get a point across
What about the rest of the readers? Would you be willing to do a share-air skills test with a new buddy on the first dive of an SD trip? Most likely while waiting for everyone else to get in the water.....
#13
Posted 28 September 2008 - 11:18 PM
The important thing is that on none of these occasions was there any panic. Urgent action yes, panic no, purely because of our joint experience.
#14
Posted 29 September 2008 - 03:38 AM
Essentially, my experience reinforces the advice given above. Remain calm and follow the procedures you were trained to do. At recreational depths, you should even be able to ascend calmly quite a ways (if your second stage is working) before your tank runs dry, at which point you could, theoretically, perform a CESA if it were absolutely necessary.
Edited by Quero, 29 September 2008 - 03:40 AM.
#15
Posted 29 September 2008 - 05:18 AM
hmmm...
If I had the o-ring go at any depth, I think I would NOT shut off the air. If I shut off the air, then water would definitely run INSIDE my first stage regulator. Surely, get with my buddy (insta-buddy usually) use his spare second stage and abort the dive. Hopefully the insides of the first stage would be kept dry.
I think Perrone was suggesting that you should get to a reliable source of gas as quickly as possible and then shut the tank down. There is also risk that if you let a tank go completely empty with the valve open that some water will get inside the tank. That can make for a messy cleanup too.
In any case, I think it is always a good idea to preserve gas in an emergency at any cost to your other equipment, particularly if the other equipment has already failed to perform normally. Even a bare tank can be sipped from to breathe. You might also be able to feather the tank valve on and off with the reg still attached to extend the amount of time you can breathe from it before it empties.
Edited by BubbleBoy, 29 September 2008 - 05:24 AM.
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