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

[gamon]

I carried a back mounted 19cf for years recently went to a back mounted 30cf. Needs 4 lbs weight offset on my hips to avoid a tendency to roll.

Don’t notice a difference and prefer the extra gas. I use it as a backup to my primary cylinder so I can end my dive with a lower reserve and therefore get more bottom time on every dive. I don’t typically start to ascend with more than 500 psi in my main tank since I’ve got the large reserve in the pony.

 

[Barnaby'sDad]

I can't remember if I have seen this somewhere. How much negative is a full Al 19? A full AL 30? A full Al 40? My understanding is a full Al 19 is one pound negative but am not sure about that.

For an AL40...I’ll just say that I swapped 1lb of lead from the tank side (left) to the opposite (right) side. I was happy enough with it...balance wise...with that change.

The only diving I ever did that I felt like the extra drag of the 40 was noticeable was river diving (strong current). All other dives, I hardly noticed it.

Part of why I carried a pony was the thought that if my buddy ran into an issue at depth...I could hand off the regular, start the ascent, and clip the tank off to him if I wasn’t otherwise task loaded.

Once you’re in the water, you don’t really notice it, so as some of the others were saying...it doesn’t hurt to carry more gas (vs. a 19 or 30).

 

[rddvet]

Just get a 40. It'll be much more easily resold in the future or you could use it if you start getting into deco diving.

 

[lexvil]

As pointed out many times in the water you’ll notice little difference, once you adjust weights to compensate it doesn’t matter much, I haven’t used a 30 but I have 13, 19 and 40’s.

im 6’5” so the 40 doesn’t really get in the way much more than the 13 but the 40 is about 5” longer than a 30 so you may find the 40 in the way a little more, maybe. 19’s pretty much disappear, if I were buying new I would do the 30 over the 19, if buying used you’ll find more 19’s and 40’s available.

 

[JohnN]

Are you planning on traveling to dive (plane, not driving). If so you won't be able to pack an AL40 in your luggage. An AL30 does hold more gas, but my AL19 with valve is ~ 11lbs. If you check the bag, that is a large part of your 50 lb budget, add another 4-5 lbs and the picture is much worse.

Take your SAC, double it, and do the math on an ascent. At a 2.0 ft^3 minute SAC, a AL19 gives me gobs of time from 100'

 

[jadairiii]

If you ever, ever think you will go tech, then listen to those (and me) and just buy a 40. There are thousands of unused 30's in tech divers garages throughout the world that did what you are thinking.

 

[RayfromTX]

If you are going to buy a small tank and it's between a 19 and a 30, I think the 19 will be more useful later when you start using a 40. I keep a 19 in my car for inflating tires and I sometimes sling one on dives in rivers and creeks. I sling it on a little harness and carry a 2 lb weight. I use my lungs for a bc and the 19 is just a hoot. It lets me do what I want with the exploring and playing with the fish and it just disappears. I can do about an hour on it and more when I spend part of my time on the surface. I haven't tried side mounting two of them but it would be fun for stuff little deeper. Its like free diving with options.

So my advice is get the 19 because it is more useful for non pony duty when you start diving with full size redundant systems and/or deco tanks where either tank you are considering will be undesirable. Honestly my 19 fills more tires than anything else these days.

 

[SaltyFrog]

I can't remember if I have seen this somewhere. How much negative is a full Al 19? A full AL 30? A full Al 40? My understanding is a full Al 19 is one pound negative but am not sure about that.

from DGX Catalina Aluminum 19.3 (3L, SHORT) Cylinder for CCR

 

[hedonist222]

Luxfer specifications

 

[rjack321]

If you ever, ever think you will go tech, then listen to those (and me) and just buy a 40. There are thousands of unused 30's in tech divers garages throughout the world that did what you are thinking.

Send them to me cheap
I like my 30, its a great O2 bottle in the ocean.

If not flying get a 30 or a 40
If flying it get a 19 (or rent doubles at your destination instead of a single and skip the pony business)