Seems logical?

[cnar]

Hi all,

I plan on getting a pony bottle and mount to increase the safety factor of my dives. I'm looking at an AL19 as my plans don't include going below or even close to 100' especially not without a buddy. I also have a much older 2nd regulator, a Sherwood Brut srb5100 which I bought 2nd hand earlier this year after I got my OW cert. This was my primary reg for a few months and is an unbalanced piston.

I'm thinking I can use this on the pony with the pony mounted up side down for better house routing. The 1st stage isn't small, compact or light and while I've used it at depths of 120' in open water obviously its not the best reg by today's standards. Because I need to change the SPG due to it giving false pressure readings I thought it would be wise to simply acquire a single SPG on a short hose and get rid of the current console altogether. In doing so I plan to remove and wrist mount the depth gauge from that console and attach the compass to a D-ring. I won't need them most times as I carry a compass on my primary reg and on my wrist but they'll come in handy when my primary reg is in for service.

Since I expect to be in the area of 60-80' max I don't foresee any issues using the Brut as a backup. I know its way larger than some regs but would this be a problem also noting that like my primary this is Yoke and not DIN?

Any feedback that can help me identify if what I plan on doing is practical would be appreciated.

 

[Diver0001]

The only issue I would have is in the handling of the pony.

The Sherwood regulator has that silly bleed thing on the first stage that would require you to leave the regulator turned on during the dive. Ordinarily one would "charge" the pony bottle by turning it on before the dive and then turn it off during the dive, only opening it if it were necessary.

The reason we do this is so that the pony (or stage) cannot accidentally purge empty during the dive. This is your guarantee that there is going to be air in it if you need it. Therefore, I would conclude that the Sherwood regulator isn't the right one for this particular job.

As for the spg, I personally think a button one that just screws straight into the 1st stage is good enough. Others would beg to differ.

R..

 

[Searcaigh]

I beg to differ short hose (4-6") for the SPG is easier to read.

Can't comment on your Sherwood reg, don't know anything about them.

AL19 might just be okay, I use an AL30 for dives over 20M and an AL13 for dives 20M and shallower.

Set up your pony and try it out at depth to check how long it will last to 50 bar /700 psi. After re-filling do another dive and switch to your pony at the end of your dive and use it to ascend from the same depth as before along with a 3 minute safety stop at 5M/15ft

If the above works for you then good, if it doesn't, then you might need a bigger bottle.

Where are you planning to mount your pony? Sounds like you might be mounting it on your tank upside down, you may need a longer hose on the second stage.

My preference is to mount the pony on the front left hand side using BC D rings, easier to handle IMHO, you should look at and try other options before making a final decision.

 

[Diver0001]

I beg to differ short hose (4-6") for the SPG is easier to read.

Yes, of course. The question is really in how often you need to read it. You need to read it when you charge the stage and then after that.....?

I have a button one on the stage I use for decompression precisely because I know how long it will last. In the unlikely event that it does free flow when I'm trying to use it, then I can tilt the stage up to check the spg again (and we do have a lost-gas protocol) but ordinarily I can judge how much gas is left in the stage by looking--not at the spg--but at my *watch*.

I know people's opinions differ about this but where we do agree is in the need to know how long he can keep diving on the pony once he makes the switch.

R..

 

[Dive-aholic]

I'm of the button gauge camp. This is for a pony that will only be used for emergencies not for the actual dive. As long as you look at it before the dive to verify the cylinder is full it doesn't matter how much gas is left in it when you're breathing it. If you start breathing off that cylinder then you are ascending to the surface. Does it matter whether you have a full cylinder or half full at this time? No. Knowing the amount of gas is not going to change your situation. You'll get to the surface and simply refill the cylinder for the next dive.

 

[knfmn]

I know I'm going to get flamed for this, but I don't even have a SPG on my pony bottle. I check the pressure on it before every dive I use it on. If I switch to my pony, the dive is over and I'm on my way up. It is just another failure point that I would have to worry about. As far as how to keep the reg, I prefer to sling my pony up front where I can keep an eye on it. I also leave the bottle on during the whole dive. I can see any possible free flows and deal with them with the bottle up front. I'm not a fan of pressurizing the reg and and then shutting the gas off. If I need to switch to the pony, I don't want to discover that the gas bled out of it and the hose and reg filled with water. Doesn't sound fun and also sounds like a recipe for problems.

Kristopher

 

[Akimbo]

I use a button or none, but you might feel comfortable with a standard SPG until you become confident you don’t need it. A button SPG is nice if you are on a boat that fills the same rig. It prevents having to remove the regulator on your pre-dive.

When I use a pony, I mount it valve-down even if the main is valve up. In addition to better routing, the damage risk is isolated — meaning it is less likely that banging into a swim step or piece of wreckage will take both out. You can also keep your rolled SMB under the valve for a protective cushion and to reduce hydrodynamic drag.

I don’t know that regulator, but you could try it and see how it works. Replace it if there is an issue.

 

[r4e]

My cave instructor made the point that your safety equipment, e.g. pony tank and spare mask, have to be of atleast the same quality as the regular ones. Considering that the pony will be hanging around with less use, you might be filling the regulator with silt etc. In a solo diving emergency, you do not want your backup set to fail. You might consider putting your better/best regulator on the pony tank!

My normal solo setup is twin 12 liter steel tanks plus a 7 liter aluminium stage tank for safety unless the return distance dictates for an even larger spare tank.

 

[divengolf]

My problem with a button is that they are not very accurate. If you loose a couple hunderd PSI because someone has bumped the purge, you'll never see it. I prefer the gauge on a short (6") hose.

 

[dumpsterDiver]

My problem with a button is that they are not very accurate. If you loose a couple hunderd PSI because someone has bumped the purge, you'll never see it. I prefer the gauge on a short (6") hose.

So if he lost a few hundred psi during the dive, what would he do? Abort and go screaming for the surface or just continue the dive and make a mental note that a safety stop might need to be truncated in the EXTREMELY unlikely event that he will actually need the pony???

I am a button guage fan myself. The new guages with 3/4 inch ? face are easy to read, even though I should be using glasses. Elimination of a hose and the spool and two dynamic O-rings is a significant reduction in potential failure points.

I armor the button guage by slipping a piece of pvc pipe over it (concentric; lengthwise) and it extends past the face of the guage. It prevents scratches and provides considerable ipact protection. i think the correct size of clear vinyl tubing over the outside would probably be even better