Any reason not to get a AL30, compared with a AL19?

[-JD-]

Absolutely. Brushed no coat all the way. If you are using a yellow or white bottle you're doing it wrong. Certainly we can all agree on THAT?!

Personally, I'd prefer the shot-blast look.

But since I've been picking stuff up used, a yellow 19 and a brushed 40 are what I rock. I guess that makes me only half wrong.

ETA: The yellow probably looks less blowy-uppy than brushed silver, so I guess that's why I have it for travel. Yea, that's the ticket!

 

[Divin'Papaw]

Personally, I'd prefer the shot-blast look.

But since I've been picking stuff up used, a yellow 19 and a brushed 40 are what I rock. I guess that makes me only half wrong.

I guess that's better than being completely wrong.

 

[Wookie]

If you're using the pony bottle to bail out from an emergency at depth your SAC rate will not be the same as during a typical dive.

I've never understood this. It's kinda like saying technical diving is harder than sport diving.

It's just diving.

Do people really not plan for gas failure, get entangled, see a shark, get chased by a turtle, have their BC bladder fail, lose a fin, lose their weights, lose their buddy, or lose their boat/upline without losing their minds?

This is the solo diver forum. If someone is out there certifying solo divers without giving divers the expectation that bad things can happen on a dive and preparation is the key to survival, and panic/increased SAC rate is what kills divers, they are doing a terrible disservice to their students. This is not OW class, where we take newbs and introduce them to the wonders of underwater, this is solo divers forum, where we expect some level of experience to come along with admittance to the class. By the time you are ready to become a solo diver, you should have a good idea about what equipment failure feels like, what losing track of your gas supply is, and what equipment you need to overcome those misfortunes.

In my mind, and the way I teach (taught) the class, is that the only thing that will kill a properly equipped solo diver is losing their minds, ie. panicking. Which leads to an increased breathing (SAC) rate, and wasting/not using the resources available to save your life.

And I have been stalked by a shark, chomped by a turtle, wrapped up so tight in net I could hardly move, completely dead empty of air, requiring a blow and go, and I hardly ever know where my buddy is. Had my SAC rate gone up, I doubt I'd be here.

 

[Wookie]

Absolutely. Brushed no coat all the way. If you are using a yellow or white bottle you're doing it wrong. Certainly we can all agree on THAT?!

Black is OK in a pinch. I only wear black until they make something darker.

 

[runsongas]

al19 can double duty as an inflation bottle, can be converted to use for ccr dil/o2, and small enough to travel with. al30 is large enough you might as well get an al40 instead.

 

[johndiver999]

I think his point is that if you are a solo Diver your air consumption should not go through the roof if you have to use your planned redundance system. There are far worse things than having to switch second stages

 

[hedonist222]

I have a cf 13 and with my SAC/NDL dives its enough

I migrated to a cf 30 only because it made no difference weight-wise.

Better to safe than sorry and its filled with EAN 40.

 

[Esprise Me]

I hope this isn't too far off-topic, but it pertains to the question of the appropriate pony bottle size. I've heard it argued that your pony bottle should contain not just enough gas for a 30 ft/min max ascent plus safety stop at a "stressed" SAC rate, but also one minute's worth of gas at the maximum depth for "problem solving." It makes a certain amount of sense to calculate that when deciding the minimum pressure to have in your primary tank before you begin your ascent. I suppose you could get entangled just as you were starting to come up. But pony bottles are more about dealing with catastrophic gas loss; without that, you still have your main tank reserve to deal with any other problems. It seems to me that by the time the pony reg is in your mouth, your problem is either already solved or probably not solvable in one minute. But I'm curious what others think. Assuming a normal SAC rate of .5 cf/min, a stressed rate of twice that, and a max depth of 100 feet, that extra problem-solving minute's worth of gas adds 4 cf to what you would otherwise need.

 

[Shasta_man]

If diving here in your stated location, I would choose the larger as the cold water adds a little effort. More than enough is a better problem to have.

And color is easy, just coordinate with the split fins

 

[SlugLife]

I hope this isn't too far off-topic, but it pertains to the question of the appropriate pony bottle size. I've heard it argued that your pony bottle should contain not just enough gas for a 30 ft/min max ascent plus safety stop at a "stressed" SAC rate, but also one minute's worth of gas at the maximum depth for "problem solving." ...

I've been researching this for the last couple days, and read a bunch of threads on the topic & even started a thread. This is not based on my personal experience, so take it with a pinch of salt-water.

• 6cu - Somewhat useless & a waste of money, except at shallow depths. At depth, it's barely better than nothing, and may prevent drowning on a rapid ascent.
• 13cu - at about 120ft is small drowning-risk, but medium decompression-risk.
• 19cu - at about 120ft is negligible drowning-risk, but small decompression-risk.
• 30cu & 40cu at about 120ft is negligible decompression-risk.

On the flip side is convivence:

• 13cu - The spare pony-tank you have on you, is better than the one you leave at home, or on the boat.
• 19cu - Probably ideal balance of weight, size, and risk-mitigation. It's also good for travel. Since this is just for super-rare emergencies, light decompression-sickness when diving near recreational-limit is probably tolerable.
• 30cu - Good, but might as well go 40cu
• 40cu - Best for multi-use, such as tech-diving, an extra/spare tank for short/shallow dives, resale-value, or even extending dives.
• 80cu - You could always side-mount 2x 80s, and just always make sure to leave enough air on both for an ascent. That said, I'd be tempted to leave the 2nd 80 cu on the boat, or at home.

I'm currently leaning towards 40 cu for multi-use. However, 19 cu is also very tempting, and probably what I'd roll with if I owned both a 40 cu and 19 cu.