Do you actually see people diving with pony bottles?

[2airishuman]

That looks indeed bigger than the one in XS Scuba.

Instead of the hassle of carrying the 19cf for your "stage" bottle (I stop using the word "pony" bottle, as I now understand how you are using it for) to extend your bottom time (right?), why not just renting the HP100, which gives extra 20cf over the AL80?

For the upcoming 13-day liveaboard trip to Indonesia, next month, 3 out of 13 of us are air hogs and we are able to get the boat to bring HP100 for them.

I find that it is rare that I have a reason to use a stage cylinder but sometimes it makes sense. I've only used them on shore dives. Usually I use something larger than an AL19, either an HP40 or an LP72.

Let's use the wreck of the Madeira, a shore dive I've made a couple times. It's a 7 minute swim out to the wreck and I find that I go through a great deal of air at this point because of the difficulty of the shore entry and the need to swim for 7 minutes. Last time I made this dive I used twin HP100s. The time before I used an HP120 and an HP40 (I think) stage, which I used for the swim out, then switched to the HP120 for the balance of the dive leaving a reserve in the HP40. The combination allowed me enough time to enjoy the wreck and make the dive worthwhile.

I suppose I could have dived with an HP149 except that I don't have one and don't know anyone who does or who rents them -- the HP120 is the largest cylinder I have. And besides I would then give up my redundancy. So the choices were the HP120 and a stage, or doubles.

On both of these dives, my gas plan involved concluding the dive with a reserve equal to 1/3 of the initial gas, which I followed, although I extended my dive once I was safely back in a shallow area near the shore exit beyond the 1/3 point since at that point I could safely reach shore without SCUBA.

This is an example of the sort of recreational dive where using a stage makes sense.

 

[rek_diver]

This is an example of the sort of recreational dive where using a stage makes sense.

Or a snorkel.

 

[2airishuman]

Or a snorkel.

On Lake Superior? Either you've never been on it, or you're kidding. The only thing less useful than a snorkel to bring on that dive is an accordion.

 

[Wookie]

On Lake Superior? Either you've never been on it, or you're kidding. The only thing less useful than a snorkel to bring on that dive is an accordion.

You mean there are people who don't dive with their accordion?

 

[Streydog]

Had to google it

 

[rek_diver]

On Lake Superior? Either you've never been on it, or you're kidding. The only thing less useful than a snorkel to bring on that dive is an accordion.

I looked up the dive after you posted about it. People surface swim to and from the wreck.

Diving the Madeira Wreck - Exposure Protection?

 

[MaxBottomtime]

You mean there are people who don't dive with their accordion?

I guess you haven't seen my new dry gloves.

 

[2airishuman]

I looked up the dive after you posted about it. People surface swim to and from the wreck.

Diving the Madeira Wreck - Exposure Protection?

If you want to swim out to the Madeira on the surface with a snorkel, great, you dive the way you want. I'm not going to dive like that. There are waves, and boats, and wind, and all kinds of things. It's much nicer, and much safer, on scuba.

 

[KevinNM]

Sure... We're often taught to keep your rig the same to develop muscle memory, right? My goal is to simply be so damn good it really doesn't matter. I could pick up anybody's rig and comfortably dive it like riding a bike. Does that make sense?

Sure. You mean like how you could easily hop on and happily go on a cross-country ride on a kickstart knucklehead, a Honda Rebel 250, or a Suzuki Hayabusa without needing any experience or training?

 

[KenGordon]

I agree with your accessment. They were "supposedly" already in safety stop. The DM managed to keep everyone calm & sharing his 2 second stages to all 3 divers. The minute that his tank depleted of air, then everyone can do CESA from 15 feet, which would be a lot safer than skipping the safety stop & risking the DCS.

My view is that a CESA involves more risk than skipping a safety stop.

A safety stop reduces an existing risk slightly. It is an option stop after a dive which ought to be 'safe' without it. On the other hand a CESA involves the risk of embolism (expelling gas too slowly - especially from shallow depths), running out (expelling gas too quickly - although from stop depth you'd hope not) and of course of DCS due to ascending too quickly.

Running out of gas under the water is always a bad choice.