Recreational Pony Bottles, completely unnecessary? Why or why not?

[boulderjohn]

I am glad you brought this up, Ken. So with this example, @tursiops and @boulderjohn what should we do about my ascent rate in my plan? Is it still too long?

I am completely baffled by this. A young woman, a student in a class, decided she needed to make a quick ascent to the surface from 6 meters and evidently held her breath in violation of the first thing you are taught in scuba.

You seem to be saying that this proves that it is absolutely essential to to take 9 minutes ascending from 80 feet in an OOA situation.

I am afraid the connection between these two topics is beyond my ability to comprehend, so I will be unable to formulate an answer. In fact, I think this whole discussion has ventured well into the kind of surrealism that would have floored Kafka.

 

[Scraps]

"Completely unnecessary" is a high bar for deciding not to carry a piece of equipment.

I routinely carry things I have never had to use in an actual emergency.

I carry a signal mirror and a whistle tucked into a pouch. I've never had to use them. As long as I manage my navigation semi-competently, it's unlikely I ever will need them. Are they completely unnecessary? So far they have been. Should I stop carrying them?

I also carry what I refer to as the world's most expensive pencil sharpener. My Navy diver son insisted I should always carry a knife--not just a Trilobite or other monofilament line cutter. So I've carried this fancy titanium knife for the last 250 dives or so. I've never needed it to cut away an entanglement. I've never needed it to subdue a megaladon or a terrorist. The only thing I've ever used it for was to sharpen a pencil . . . and then I promptly forgot the pencil was made of wood and untethered--and let it float away from me. Is the knife completely unnecessary? Should I stop carrying it?

I often carry a pony bottle when I spearfish with a buddy I know would rather kill one more grouper than save my life. The only times I've used it have been to verify my calculations that it holds enough air for me to ascend safely from 100 feet with a safety stop. Is it completely unnecessary? I don't think so because it's sound doctrine always to have air redundancy immediately available--and the octo on a buddy who is chasing fish isn't immediately available even if I can still see him.

Just because the circumstances that might turn "completely unnecessary" into "vitally necessary" would almost certainly involve errors on my part does not mean I should't carry the completely unnecessary gear.

 

[Blackcrusader]

Wow what a rugged few pages of reading added. Here is my 2 cents.

In the last decade of diving in Asia I have never once seen any recently certified diver and even those who have AOW with even 50 dives do any gas planning on recreational dives. I have never seen a DM do a gas plan for a recreational dive for any depth. When I have asked an OW or AOW diver about their RMV or Sac rate they look at me with the I do not comprehend your question. They simply have not been taught and they have not tried to ever work it out on their dive logs. All they know is the guide tells them to notify when they get to half tank and again at 50 bar. A lot of guides will bring divers from say 25m depth with 100 bar to shallower depths to make sure the divers can finish their 1 hour dive with around 40 or 50 bar. A lot of guides are good at judging their customers as they monitor their air on the dives. Let's face it a lot of OW and recent AOW divers still rely on guides and enjoy their relaxed fun dives this way.

As they dive in groups they always seem to have another diver nearby. Close enough to get to in an OOA situation if they have not shot to the surface by themselves. I do not do gas planning for recreational dives even when diving to 45m depth. Never seen a recreational diver sit down and do a gas plan either and that is even with DM and instructor certified recreational divers. Do I think recreational divers need a pony bottle? No.
Would I tell a diver not to learn how to use one or to have one? No.

Would I plan to allow 9 minutes to get to the surface in an OOA from 25m? No

 

[Blackcrusader]

You didn’t read past this question did you?

I did read past it. You have never answered the questioning to your statement.

I also forgot to mention the benefit of my partner running out of air, I can simply give them the pony for ascent. I like that significantly more than having an unknown buddy attached to me for both my safety and theirs.

I would have thought that unless an equipment failure a buddy monitors his dive partners air during the dive as well. I certainly do and if my buddy is getting low on air then it's safety stop and surface or maybe share air from me till we get to the safety stop.

 

[TMHeimer]

Pony bottle for me depends on type of diving. I haven't used mine in many years because my dives rarely exceed 30 feet. I almost always finish the dive with way more psi than needed. But, I have used it for dives that approach or exceed 100'. Also at times for 89' dives if I'm not familiar with a buddy's ability. Other than these situations, it's not worth the hassle of even attaching it up. Plus you have the (minimal) cost of fills.

 

[Ayisha]

BTW I checked my copy of the Fundamentals book and it doesn’t mention ascent rates as far as I can tell. More modern books warn about people on the internet though.

Ascent rates, including the 10 feet per minute ascent from 50% of a max 100 foot depth, are in the Fundamentals course materials and Standard of Procedures.

That book is really just an overview of the basic principles. It doesn't give the specifics or calculations, etc.

 

[Ayisha]

This thread reminds me of the "spirited" debates from the early and mid-2000's.

I hope we don't go there again.

 

[MrBigfins]

I did read past it. You have never answered the questioning to your statement.




I would have thought that unless an equipment failure a buddy monitors his dive partners air during the dive as well. I certainly do and if my buddy is getting low on air then it's safety stop and surface or maybe share air from me till we get to the safety stop.

Poor wording on my part, I was referring to my buddy actually being out of air not running low. Equipment failure or failure on the part of the buddy. I will occasionally check with a random buddy during the dive and adjust depth Accordingly, but that doesn't mean it couldn't happen.

 

[KenGordon]

Ascent rates, including the 10 feet per minute ascent from 50% of a max 100 foot depth, are in the Fundamentals course materials and Standard of Procedures.

That book is really just an overview of the basic principles. It doesn't give the specifics or calculations, etc.

The OP is thus taking 8 minutes rather than 5 and a bit that GUE would suggest - assuming 25 to 22 takes 1 ish minute and 12 to 0 takes 4, or am I forgetting 6 minutes 6 to the surface?

So what is the procedure for an AS ascent?

 

[KenGordon]

This thread reminds me of the "spirited" debates from the early and mid-2000's.

I hope we don't go there again.

I don’t think that is a risk. He doesn’t represent anyone as far as I can tell and covers over like someone who missed the point and has not really understood what was being taught.