Solo and the Octo

[Nemrod]

webdivbc, what OOAD? we are solo! so the only one possibly out of air is us. And if it were me I would rather have another source of air and regulator rather than an octa hooked up to an empty tank. Of course, the surface is a redundant supply, thus the old rule never to dive below twice your comfortable free dive depth--unless you have real redundancy and an octa is not redundancy at all, it is just clutter for a solo diver. N

 

[wedivebc]

webdivbc, what OOAD? we are solo! so the only one possibly out of air is us. And if it were me I would rather have another source of air and regulator rather than an octa hooked up to an empty tank. Of course, the surface is a redundant supply, thus the old rule never to dive below twice your comfortable free dive depth--unless you have real redundancy and an octa is not redundancy at all, it is just clutter for a solo diver. N

Did you read the entire thread Nemrod? He was asking about a suitable configuration for solo and when he's with a buddy.

 

[2TH DIVR]

I agree fully with Nemrod.
If I do a dive that I would need more than a 13 pony, I go with duals. Just think any thing bigger makes me unbalanced.

 

[eanxgirl]

Guess I am one of the few who disagree. To me the primary tank is just that....primary. I, personally, like having a reg and octo off the tank. I have had reg problems and switched to the octo. The octo isnt just for someone else to use that is having air problems. As a solo diver I think making the primary tank as available as possible is just a good idea. Since the odds are that while I dive a pony....I wont need the pony. So I place the pony reg on my right hip just under the bottle itself (cam strap rig) and not prominent on the chest. I keep the octo prominent on the chest.
All regs are breathed out of regularly to ensure functionality.
I still like the idea of an octo....you dont...fine.
rich

I agree with you Rich. I was at 110 feet this weekend when my primary started free flowing. I was not diving solo but would have handled the problem in the same way if I was solo. When I got the free flow I was able to breath from my octo and fix the free flow problem on my primary. I was then not forced to abort the dive or breathe my pony. I continued a very pleasant hour-long dive with my redundant air source intact.

 

[Blitz]

Personally I would dump the octo for streamlining sake.

 

[Scuba]

From a redundancy perspective you are only adding second stage redundancy to your main (larger) gas supply while adding a potential failure point, although rare. The addition of an octo on the same gas source will not offer redundancy in the event of a first stage malfunction, such as free flow or freeze up where it has to be shut off for a short period of time, in the event of a hose rupture, or blown o ring. To fully protect the main gas source consider an H or Y valve. Consider it adds additional failure points to what already is a fully redundant gas system with the pony.

In the example given, where second stage free flowed and octo was used while correcting the problem without using the pony gas supply. It’s not a very big advantage when you consider it only covers a few specific circumstances, while not others as mentioned above. You also have the option of switching to the pony, if you are able to quickly solve the issue the gas used from the pony may be negligible in terms of hindering dive plans, or may not, hence a slim advantage in very limited conditions to the octo in these cases which have to be weighed against its potential as an additional failure point. A rare event.

In the case of buddy diving you have the option of donating the pony or your breathing second stage if you don’t have an octo.

As noted by others the primary reason for an octo is to share air with a buddy. Given that you use the same redundant configuration with buddy and solo diving, the octo doesn’t have much to offer in terms of its usefulness. On the other hand, it doesn’t detract much either as it will rarely malfunction if properly cared for and has negligible impact on streamlining if properly configured.

It comes down to unnecessary gear from a safety standpoint. Offering a small convenience - not a safety advantage, and a small safety disadvantage, as I see it. Assuming the dive plan considers the smaller gas supply as the determinant factor in establishing a safety limit.

Of course, the surface is a redundant supply,

I understand the point you are trying to make, but the surface is not usable underwater like an additional tank and reg. is. I would characterize it as a potentially easily reachable escape option. Your statement below confirms this.

thus the old rule never to dive below twice your comfortable free dive depth--unless you have real redundancy

I've heard this, but disagree, why just two and not three times as deep, or 4, or 10, or 20. Whats the difference? So you made it half way, and then what? A little bit further, and then what? Right about when the boogie man comes a knocking, you're supposed to stay calm and not open the door? Maybe its a useful rule for some, calm, cool and collected experienced divers, but not for many others. Again, I understand the point being made, but disagree with it from a safety point of view and its use as a general rule for all divers. Comfortable depth, where one can reliably and consistently safely ascend should be the guideline. Otherwise, the risk is great.

 

[Nemrod]

Scuba, the reason the old rule says twice your free diving depth--and it is not my rule---it was taught me and it is in old dive manuals --vs as you said 4 or 5 or 6 or whatever times is really very simple to understand. To put it another way never dive deeper than the distance you can swim underwater without having real redundancy (we talking solo here) because that is the distance or depth from which you should be able to safely reach the surface after a problem. When you freedive, as you well know, say you can comfortably freedive 30 feet--well, then that is an overall round trip distance of 60 feet and thus your solo or no redundant equipment max depth is 60 feet--not 90 or 120 or 300. Like I said, it is a rule I mostly follow but it is not my rule. When exceeding that depth--especially solo--then I feel I need real redundancy and that means something other than an octa.

"Did you read the entire thread Nemrod? He was asking about a suitable configuration for solo and when he's with a buddy.'
Uh, yeah, and this is the solo forum so my answer was specific to that and not buddy diving

Look, in a discussion, which this is, people say and explain their ideas, you can take them, leave them, study them, exclude them, incorporate them as you see fit, I certainly do. Several threads on this board have recently influenced my diving style, always something new and old to learn.

My opinion, the octa is a buddy breathing replacement developed by the dive agencies to make diving easier and safer and less training/practice intensive when BUDDY diving. It is a poor substitute for solid redundancy when solo.

Let's face that there is an anti pony sentiment in this board--just look at recent threads. The octapus is a topic like solo that is treading on the verge of sacriligious because it is so ingrained in most training you must have a buddy---you must have an octa etc---sorry, I don't buy in on it. N

 

[RICHinNC]

Def agree with you Nemrod on opinions and stances here. While we disagree on the octo...I think you should be able to have and state your opinion. It would be easy to list a number of member that may say that....but dont demonstrate it.


And as far as handing off pony....not in the cards. Its mine...totally. If you have an air problem...I will have an octo you can use.
rich

 

[DA Aquamaster]

From a redundancy perspective you are only adding second stage redundancy to your main (larger) gas supply while adding a potential failure point, although rare.

I should add here one more reason why an Air 2 is a worthy addition for a solo diver who may also on occasion dive with a buddy (as most solo divers do). You are completely correct that an additional second stage poses additional risk for failure. However, should an Air 2 fail and begin freeflowing, it can easily and quickly be disconnected and isolated with minimal loss of gas.

The addition of an octo on the same gas source will not offer redundancy in the event of a first stage malfunction, such as free flow or freeze up where it has to be shut off for a short period of time, [or] in the event of a hose rupture, or blown o ring. To fully protect the main gas source consider an H or Y valve. Consider it adds additional failure points to what already is a fully redundant gas system with the pony.

An H or Y valve will not fully protect the main gas source as it will not protect you from a blown neck O-ring or a blown burst disc. Consequently they are not the equivalent of independent doubles or isolator manifolded doubles in terms of redundancy or, in most cases, gas capacity.

If I do a dive that I would need more than a 13 pony, I go with duals. Just think any thing bigger makes me unbalanced.

In my experience diving a 30 along side a steel 72 is not an issue while swimming but will produce a slight rolling moment when motionless in the water. In contrast double 72's are extremely stable and offer very little additional drag compared to an AL 30 / steel 72 combination.

 

[DA Aquamaster]

Look, in a discussion, which this is, people say and explain their ideas, you can take them, leave them, study them, exclude them, incorporate them as you see fit, I certainly do. Several threads on this board have recently influenced my diving style, always something new and old to learn.

My opinion, the octa is a buddy breathing replacement developed by the dive agencies to make diving easier and safer and less training/practice intensive when BUDDY diving. It is a poor substitute for solid redundancy when solo.

Let's face that there is an anti pony sentiment in this board--just look at recent threads. The octapus is a topic like solo that is treading on the verge of sacriligious because it is so ingrained in most training you must have a buddy---you must have an octa etc---sorry, I don't buy in on it. N

I agree with what you are saying here.

The larger issue affecting many topics on this board is that many if not most divers are making decisions about their diving equipment and techniques based on indoctrination rather than on experience and critical thinking.

The indoctrination versus critical thinking issue is a major concern in the field of ethics right now where it has become painfully apparent that you cannot teach people to resolve ethical dilemmas without also teaching them to use critical thinking skills to avoid the pitfalls and psuedo-ethics that result when you make decisions solely on indoctrinated beliefs. The well publisized abuses and excesses in military prisons and interogations is a prime example of what can happen when that occurs. (Please don't take this as an anti-military stance as it is not - I come from a military background but also from a military backgorund and training steeped in the Calley/My Lai expereince where the moral obligation of an officer to refuse an immoral order was emphasized frequently and repeatedly.)

In regard to diving, training agencies (like the military and many businesses, employers, etc) rely on indoctrination to convey a maximum amount of information in a minimum amount of time. The problem is that many if not most of the divers trained in this amnner are not well versed in critical thinking skills (that are for the most part no longer taught in public schools) and consequently adopt the indoctrination they receive as the "truth" and view it as applicable and appropriate in any and all situations.

This view is apparent in divers at the Open Water level all the way up to trimix cave and wreck divers, although as the experience level (not strictly the training level) rises, the reliance on indoctrination tends to decrease as divers experience and observe more and more situations where equipment or techniques not consistent with their indoctrination not only work but in particular cases work better than what they were trained to do.

So it is inevitable that divers who approach diving from a critical thinking perspective where they engage in a critical self analysis of the reasons why they do everything a particular way and evaluate how well a partiticular item or technique meets their specific needs and then adjust or modify their equipment or techniques accordingly, will always conflict with divers who rely on indoctrination and make choices in techniques and configuration soley on how they were trained or based on what they have been told by an authority.