Pony bottles/spare air

[flots am]

Same here. With the pony, the octo on primary is not useful at all. The SDI Solo course recommends this as well. One less thing to fail (octo on main primary) and one less hose to tangle/be in the way.

I'll have to go back and check the book, but I don't believe they actually recommended "no alternate second stage on your main tank" for a solo diver.

SDI recommends an alternate redundant air source, but I don't think they actually discourage alternate second stages in the solo class.

flots.

 

[je76]

No I dive doubles with an isolator.

Should I suffer a failure in a second stage I shut down the post where the failure occurred which still gives me access to the gas in both tanks and my pony acts as my regulator redundancy on a separate system. If I have to isolate, same deal and the gas in my pony now may become more important since I have lost the volume left in the failed tank.

Answering part of the original question I would never want the pony hooked to my primary system. I want an independent redundant system that acts as another layer of protection. 3 is 2, 2 is 1 and 1 is none.

I am not sure I am sold on this aspect of side mount (meaning without a pony). Should you suffer a failure in one of the tanks that tank is lost entirely unless you change regs underwater. My LDS has a considerable number of tek side mount divers and they all dive pony bottles specifically for this reason.

 

[flots am]

I am not sure I am sold on this aspect of side mount (meaning without a pony). Should you suffer a failure in one of the tanks that tank is lost entirely unless you change regs underwater. My LDS has a considerable number of tek side mount divers and they all dive pony bottles specifically for this reason.

Not sure what you mean here. With sidemount, both tanks have a first stage and a second stage, and the diver switches between them during the dive to equalize gas usage.

flots.

 

[DevonDiver]

No I dive doubles with an isolator.

Then I fail to see why you'd need a 'pony'... even for technical dives. There comes a point where unnecessary redundancy poses a hazard in itself - task loading, complexity, weighting/buoyancy...clutter.

I don't know of a tech agency that advocates triplicate redundancy... but I know most of them do advocate minimalism-to-task and rationalized needs.

Should I suffer a failure in a second stage I shut down the post where the failure occurred which still gives me access to the gas in both tanks and my pony acts as my regulator redundancy on a separate system. If I have to isolate, same deal and the gas in my pony now may become more important since I have lost the volume left in the failed tank.

What you seem to be describing is an open-circuit bail-out to an open-circuit rig. What consideration do you give to the gas-management issues of pony capacity? Exactly how much gas are you provisioning for... and what parameters of dives??

I am not sure I am sold on this aspect of side mount (meaning without a pony). Should you suffer a failure in one of the tanks that tank is lost entirely unless you change regs underwater. My LDS has a considerable number of tek side mount divers and they all dive pony bottles specifically for this reason.

Which is odd... because if those 'tek side mount divers' had been trained, they'd be equipped to feather breath tanks and/or swap regs. Both are techniques the permit access to 'failed' cylinders (still not sure exactly what failures you're referring to).

Again, no current sidemount training/course/agency advocates a bail-out/pony for either recreational or technical level sidemount diving...

In any event...regardless of dive parameters, proper gas management and planning ensures the diver has sufficient gas to survive a failure - sidemount or backmount.

Perhaps more technique, and less kit, loaded into the equation?

 

[flots am]

I am not sure I am sold on this aspect of side mount (meaning without a pony). Should you suffer a failure in one of the tanks that tank is lost entirely unless you change regs underwater. My LDS has a considerable number of tek side mount divers and they all dive pony bottles specifically for this reason.

It's likely that what you saw was deco gas, not a pony bottle. The difference is the contents.

A pony bottle typically contains a mix that's breathable wherever you might need it (usually air), while a deco tank contains a higher mix of O2, but is toxic at depth.

A side-mount diver already has two fully redundant sources of breathing gas. "Planning" is what makes either tank usable to end the dive in an emergency. A third tank isn't necessary.

flots.

 

[je76]

Devon, Well I am not sure what you are driving at? I was explaining the approach that I was taught in relation to the question asked and not looking for a critique on the system and approach I was taught.

That being said I am sure that the instructors that I dive with and the course director who instructed me could debate the point with you. I will not. I would add that I will be sticking with what has worked for me and my dive team over the countless thousands of dives that we all have collectively.

Diving doubles with a pony is not uncommon here in the northeast and is in fact required by some dive boats and operations.

For my part I have managed my deploying my pony, a large slr camera, while towing a float and doing a hover at 30 feet during a night dive. I have had no issue with task loading or equipment management.

As for side mount divers, again I cannot comment and was only pointing out what I felt was a shortcoming of the system.

 

[GrumpyOldGuy]

Diving doubles with a pony is not uncommon here in the northeast and is in fact required by some dive boats and operations.

Which boat? I have heard references to a few that require redundant gas but doubles with an isolator OR a pony, not both.

 

[je76]

Thanks flots am but I understand the difference between a deco bottle, stage bottle and pony bottle.

Maybe it is a difference in approach based on our LDS CD's experiences diving for the last 25 years. This is the way I was taught and will continue to dive. I have never had trouble managing a pony on any dive that I have done and typical Jersey dives involve quite a bit of gear even for relatively simply recreational dives never mind decompression dives. If the pony's presence endangered me I would simply un-don it and ditch it as I have been trained to do.

I have done Meg Tooth dives in N.C. with divers wearing manifolded doubles, staging an alum 80, hanging deco gas, using a scooter to dig while running a line and still wearing a pony. Despite all this gear still managed to pull up around 40 meg teeth.

---------- Post Merged at 07:00 PM ---------- Previous Post was at 06:54 PM ----------

Ahh, you gonna check on me?

As an example it used to be stated explicitly on the Ol Salty IIs website to name one.

---------- Post Merged at 07:12 PM ---------- Previous Post was at 06:54 PM ----------

Here you go Grumpy, Straight from the Capt Jim at the Gypsy Blood's website;

"The second is redundant air supply. All divers MUST dive with a pony or stage bottle with a separate regulator, including students. There will be no exceptions to this rule."

This being said how stringently Capt Jim enforces it on all divers with doubles I cannot say, but it is the policy of that boat and a few others. Looks like the Ol Salty IIs website no longer says it but it did when I started diving 5-6 years ago.

Of course what a dive boat's insurance company says is good policy and what is good policy for a diver is a different story altogether so their policies don't support my argument.

~~~~~~~~~~

**Now this conversation is starting to sound like one of those argumentative threads on here where people are trying to make a point and/or tell someone how to dive, which I am not. Next thing you know we will be talking about what kind of wing I use and if it has bands or not. It was because of these types of things that I typically avoid forums like this.

I was just trying to point out the system and the mindset that I was taught and use and wasn't asking a question or looking for an instructional.

 

[Akimbo]

… There comes a point where unnecessary redundancy poses a hazard in itself - task loading, complexity, weighting/buoyancy...clutter…

Something like this guy?



Remind me agian, we are doing this for fun right???

 

[DevonDiver]

Devon, Well I am not sure what you are driving at? I was explaining the approach that I was taught in relation to the question asked and not looking for a critique on the system and approach I was taught.

Not driving at anything - just enjoying a discussion

It's odd, because I've never heard of the practice of 'triplicate redundancy' before - either stated in agency training materials, or as an operating practice advocated by any experienced technical diver.

Properly configured doubles/sidemount, plus effective gas planning and management, offers sufficient safe-guard/fail-safe against all reasonable and foreseeable problems.

I'm merely questioning what 'need' you feel there is for an additional pony/bail-out? i.e. risks that aren't already effectively mitigated by existing equipment configuration and diving protocols/procedures?

For my part I have managed my deploying my pony, a large slr camera, while towing a float and doing a hover at 30 feet during a night dive. I have had no issue with task loading or equipment management.

If we assume a dive will always transpire under the best case circumstances, then equipment configuration and dive protocols become pretty much irrelevant. However, given a worst case scenario - most experienced technical divers will testify that simplicity of equipment/protocol becomes a potential life-saver.

My only advice is to put it to the test and see for yourself. Try running through some rescue scenarios etc etc. Try dealing with multiple simulated failures/issues. See how you make out.

It's very easy to fall into the mindset of "add..add...add". We conduct dives, nothing tests our premise, and we feel we are 'safer'. It's an illusion.

As for side mount divers, again I cannot comment and was only pointing out what I felt was a shortcoming of the system.

Which, to be fair, is based upon a lack of understanding of how the system is taught.