Question on air source for dive buddy

[wetb4igetinthewater]

Okay, so I'm quite new to diving (OWC late June, now up to Rescue Diver with 42 dives).

My question has to do with the air source that I would provide to my dive buddy. I dive with 120 cu ft tanks and a 19 cu ft pony bottle. My primary dive buddy, former PADI instructor, tells me to lose the octopus for my main tank, as my dive buddy would use that from my pony bottle. He does a lot of DPV diving and tells me to get more streamlined. I can understand this absolutely, but not at any expense at safety.

A divemaster assisting in the search and recovery class I took last weekend advised me to have an octopus and the pony bottle is for me only.

So, I figured I'd ask here to get some advice. What is the generally recommended setup when you have a pony bottle. Is it any different than if you don't? I.e., is the pony bottle just an addition of equipment and you don't subtract anything.

Thanks in advance.

 

[Txredneck]

It seems to me, and I've less training experience than you, but seems to me that the Laws of Murphy would prevail over streamlining...

 

[Tony387]

I dont use an alternate second stage when im diving with a pony. Your pony is your alternate in the event of first or second stage failure, and its yours. I would donate my long hose primary if I need to share air with a buddy.

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[Steve_C]

Speaking as a NC diver diving from a boat. Dive both.

If you are diving thirds, then if your buddy goes out of air at the worst possible time your 120 provides 40 for the buddy and you and gets you both back to the anchor line and up to the boat. If the buddy has only your 19 it is free ascent time. Not optimal.

If you have a total air failure and your buddy is around you use their air to get back with the pony in reserve. If not the pony safely gets you to the surface.

I sling my 19 pony. What I would do, and discuss with my buddy, is that if either has a total air failure, we air share back to the anchor. Once we are back at the anchor I would pass the pony over and hook it to my buddy if they are the one out of air otherwise I keep it. During the ascent we would quit the air share. This gives us both enough air to finish the dive. He/she has 19 and I have probably around 30 ish assuming they are the one out of air. It is much easier to do the safety stop and then do a controlled return to the boat not doing an air share.

Note that your buddy may need to do an oral inflate of the BCD if they are totally out of air so be ready to pop their weights at the surface if this poses an issue for them. Same holds for you. Need to orally inflate.

 

[pasley]

19 CuFt Pony bottle.

1. Assuming The bottle is full. On dive boat last Sunday I was talking to a diver about his pony bottle and I mentioned this and he said "If it was empty this turkey timer thing would pop up.......What the?!.... It is out of air!? It was filled and never used, but obviously had a leak. Gauges you can read the PSI on work best.
2. Assuming a SAC in a panic situation of .7 (1.2 would probably be more realistic).
3. Assuming the other diver does not drop it on the way up. Easy to do in the water when you are trying to vent air from BCD or Drysuit, Check The surface, Check air pressure, and hold on for dear life to you buddy all with only one hand because the other one is holding a 19 CuFT tank!

What the 19 CuFt tank gets you at a SAC of 0.7.
0 Feet = 27 minutes of air
33 Feet = 13.5 minutes of air. Time to surface w/o safety stop. 1 minute
66 Feet = 9 minutes of air. Time to surface w/o safety stop, 2.2 minutes
99 Feet = 6.7 minutes of air. Time to surface w/o safety stop. 3.3 minutes.
132 Feet = 5.4 minutes of air, Time to surface w/o safety stop. 4.4 minutes.

Everyone will have their own position of what is right. But it seems to me the following should be considered:
1. The poor blighter who ran out of air has enough on his/her mind with out having to hang on to a large 19 CuFt tank and hoping it is enough air to get to the surface.
2. The tanks on you back will probably have more air in them and do not require a one handed juggling act as described above.
3. Is the pony bottle full to 19CuFt at the time of need?
4. The Octo comes with a gauge you can monitor so you know how both your air supplies are going on the way up.
5. The Octo simplifies the one hand management of task (gauges to check ascent speed, venting air, checking surface, and maintain a death grip on your buddy just in case you need more help) and will make it easier on someone who is already feeling stressed.

 

[wetb4igetinthewater]

I would add, I do have a simple SPG attached to my pony bottle, for just in case Murphy was an optimist. And yes, I had a nagging suspicion that the streamlining advise I received was a bit too much as it sacrificed safety. So, thanks everyone who answered! I be restored an octopus to my first stage for my main tank. My pony bottle will only have one regulator. I just finished packing the car, as I have a DPV class tomorrow. Can't wait! Good night to all!

 

[hroark2112]

The other thing to remember is that a panicked OOA diver is probably not going for your pony or octo. He's going for your primary. Removing your octo means that now you're on the pony.

Smart call all not to remove the octo!!

 

[Colliam7]

My question has to do with the air source that I would provide to my dive buddy. I dive with 120 cu ft tanks and a 19 cu ft pony bottle. . . . What is the generally recommended setup when you have a pony bottle.

The very specific, focused, and laser-like answer is, . . . it depends. Both views are reasonable. I personally favor the approach articulated by the DM - keep your pony bottle for YOU. But, in an OOA situation, I could also hand off my pony to another diver and potentially simplify the ascent, if circumstances support doing that.

When I dive with a single main cylinder and a pony, I keep my main cylinder regulator configuration 'standardized' - primary second stage on a long hose, alternate second stage on a shorter hose, with a bungee necklace. In the event of an OOA (dive buddy) I donate the second stage in my mouth, go to my alternate, hold my buddy and ascend. I carry my pony bottle as an independent gas supply, for use in the unlikely event of going OOA (me), because of some catastrophic equipment failure.

Keeping the alternate / second hose on my backgas reg also gives me some flexibility - if I decide to not use my pony on a particular dive, I don't need to attach another hose / second stage - it is already there.. And frankly, the comment about streamlining is a non-starter. The same argument (lose a hose, streamline, etc) is used as some sort of justification for eliminating the HP hose and going with wireless air integration. It simply is not possible to discern any quantitative 'streamlining' benefit of having one less hose. Streamlining is more about hose routing (and hose length) than hose number, more about eliminating unnecessary accessory gear dangling from clips on the BCD, more about eliminating the wing 'taco' from an oversize wing, than it is about the number of hoses.

Having said all of that, when I dive a sidemount configuration, using two independent, main cylinders, I only have one second stage on each regulator. The regulators are specifically set up for sidemount diving, and I would not use them for single cylinder backmount diving, so there is no issue of adding a hose for diving a different configuration. Nonetheless, I acknowledge that, in that particular case, I may be doing what you instructor buddy suggests.

He does a lot of DPV diving and tells me to get more streamlined.

That advice, in itself, is very good, even though there is little streamlining benefit from eliminating a hose. And, when you are using a DPV, you are potentially more likely to sense the drag associated with a non-streamlined rig (at least I subjectively feel that way). But, if he goes on to say he can discern the specific difference between having two (properly routed) second stage hoses vs one, I have to wonder what gas is in the pony bottle.

At the end of the day, do what you feel most comfortable with.

 

[Instructor_Tom]

Loose the pony bottle and learn proper gas management. You should never carry an extra bottle unless you actually need the gas for the dive.

PADI teaches you to donate your second to an OOA diver, in actually what you will learn is that they will grab the primary right out of your mouth and if you continue on into technical diving you are actually taught to give up the reg in your mouth.

Streamline means get rid of everything you don't need for that dive.


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[Jeffrey A. Cogan]

What about an Air 2 Scuba Pro. No octo, your inflator hose has a regulator on the end. Give the primary to the buddy, since he is going to take it anyways, use the Air2 to ascend. You have your cake and eat it to: streamlined but still have air to breath and recognize that the buddy is grabbing your primary. I am looking for the pros-cons of the Air2. 25 dives - Open Water - May going for AOW.