Simple question about removing backup regulator
- Thread starter mcavana
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R
redacted
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You may want to do the math again. First off, if you go OOA at 100 ft you will need to immediately start heading up. On the way, grab that spare air and start breathing. Keep your airway open but don't breath too much. If you do it right, you will hopefully be reasonably close to the surface before you go OOA again.
You really would be much better off with a small pony. You would be able to do a normal ascent including a rest stop.
Hatul
Contributor
I agree with others, the big problem in your post is the SpareAir as your backup, it's just not enough. Better get a small Pony tank 13 cu ft or so, and even then, why not leave the secondary regulator in place. In the event of a air supply problem you need some time to sort things out, you'll probably be hyperventilating and have enough air to make a controlled ascent.
Adam
Adam
Yea, it's those freak instances that can spell the end. Nobody plans to get in trouble.
Free flowing regulators, blown o-rings and hose failures are some of the possible big problems that can and do occur. Any of those could deplete your primary cylinder fast. That means you really want a robust back-up when going solo to a significant depth. Going solo to 100 feet wants to be very carefully considered.
As far as removing your alternate I would not rush to do that. For instance, should your primary mouthpiece fail (come loose, tear) switching to your alternate is a seamless recovery. Only with major redundancy, like doubles would I consider limting access to your largest breathing air suppply.
As for redundancy this may help you establish a realistic capacity.
Pete
TheScubaBOB
Contributor
The Spare Air is a toy. There is so much that can go wrong on any dive.
What if you get entangled? This one thing could cause a few situations where you'd want more than a minute of air.
Imagine you get entangled near the end of your main cylinder air supply (and the NDL). While freeing yourself you exceed the NDL so you now must do a 3 minute safety stop? can you get to the SS, do it & surgafe on 3cf?
Or even worse you breath your main cylinder dry while freeing yourself (before finished), is 3cf going to give you the time to free yourself & get to the surface?
I'm interested in Recreational Penetration of Wrecks so I have a 30cf Pony Bottle, it's attached to my main cylinder with the regulator on a necklace. All together the used 1st & second stage Regulator (including cost to have them serviced) the the AL pony bottle cost $300 - $350! how much more is that than your Spare Air?
What if you get entangled? This one thing could cause a few situations where you'd want more than a minute of air.
Imagine you get entangled near the end of your main cylinder air supply (and the NDL). While freeing yourself you exceed the NDL so you now must do a 3 minute safety stop? can you get to the SS, do it & surgafe on 3cf?
Or even worse you breath your main cylinder dry while freeing yourself (before finished), is 3cf going to give you the time to free yourself & get to the surface?
I'm interested in Recreational Penetration of Wrecks so I have a 30cf Pony Bottle, it's attached to my main cylinder with the regulator on a necklace. All together the used 1st & second stage Regulator (including cost to have them serviced) the the AL pony bottle cost $300 - $350! how much more is that than your Spare Air?
Got a Spare Air in our shop for rebuild and once it was complete did a little experiment: I went belly down at the bottom of the pool, 9'. Switched to a FULL Spare Air 3cf and started breathing. Not stressed, just lying there. Got 20 breaths and then it went OOA. No warning like a reg starting to breathe hard, just crapped out. Luckily I had my primary ready to go...
Solo diving to 100 feet should be undertaken with serious attention to training, preparation and redundancy. Should anything go south when at 100', or 80' for that matter, have backups in place and the training to implement them. A small problem can turn into a big issue very quickly. Just my .02.
Solo diving to 100 feet should be undertaken with serious attention to training, preparation and redundancy. Should anything go south when at 100', or 80' for that matter, have backups in place and the training to implement them. A small problem can turn into a big issue very quickly. Just my .02.
Jorgy
Contributor
I believe there is more to sizing a pony tank that just a calculation..........
Simply put the larger the reserve the more time you have at any depth......the more time you have the more options you have.........
For example...........
Depth 100 feet......did you follow the anchor line down? How far are you from the anchor line..............could you return to the anchor line for your ascent........
Will you do an open water ascent?. .......or try a follow the bottom contour to shallower water.........
Are you in area of boat traffic?..........could you, should you shoot a DSMB..........
What if the cause of the OOA happens just after you got tangled in fishing line?........and you need to free yourself first..........
How long have you been at 100 ft?.......there is not such thing as no-deco diving, even recreational diving takes into account a slow surfacing (30 ft/min max ascent rate) .....so from 100 ft it should take over 3 minutes just to travel the distance to the surface.......personally, I would prefer to do even a longer safety stop (at least 5 minutes) if I go directly to the surface at 30 ft/min...............so that is a minimum 8 minutes to get to the surface for me.............
My point is that a person with a say a 40 CU FT tank, could have a burst disc go at 100ft and other than the noise not be to concerned.....now the same person with much smaller tank (not picking on just Spare Air here) may be much closer to the emergency-get-the-surface-right-now mode..........
Any reserve is better than nothing.............this is just a case where more is always better...........
I originally went with a 19 CU FT myself (based on calcs), now with hindsight I would have gone at least with a 30.........or maybe even bigger...........DIR folks use AL 80's........
M
Simply put the larger the reserve the more time you have at any depth......the more time you have the more options you have.........
For example...........
Depth 100 feet......did you follow the anchor line down? How far are you from the anchor line..............could you return to the anchor line for your ascent........
Will you do an open water ascent?. .......or try a follow the bottom contour to shallower water.........
Are you in area of boat traffic?..........could you, should you shoot a DSMB..........
What if the cause of the OOA happens just after you got tangled in fishing line?........and you need to free yourself first..........
How long have you been at 100 ft?.......there is not such thing as no-deco diving, even recreational diving takes into account a slow surfacing (30 ft/min max ascent rate) .....so from 100 ft it should take over 3 minutes just to travel the distance to the surface.......personally, I would prefer to do even a longer safety stop (at least 5 minutes) if I go directly to the surface at 30 ft/min...............so that is a minimum 8 minutes to get to the surface for me.............
My point is that a person with a say a 40 CU FT tank, could have a burst disc go at 100ft and other than the noise not be to concerned.....now the same person with much smaller tank (not picking on just Spare Air here) may be much closer to the emergency-get-the-surface-right-now mode..........
Any reserve is better than nothing.............this is just a case where more is always better...........
I originally went with a 19 CU FT myself (based on calcs), now with hindsight I would have gone at least with a 30.........or maybe even bigger...........DIR folks use AL 80's........
M
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