Silly to buy Al40 as first tank?

[teknitroxdiver]

I think your reasoning is spot on, and I'm seriously considering an AL40 for exactly the same purposes.

 

[halocline]

2. Post-dive: I would like to be able to soak my regulators pressurized. I get a lot of mixed information about whether rinsing is sufficient or if soaking is necessary, but others suggest that soaking is dangerous due to leaky dustcover or water coming in via second-stage. So the safest approach seems to just soak my regs pressurized.

Don't listen to the ninnies that say you can't soak a regulator with the dust cap. That's precisely what they are for. The only exception is a regulator with an anti-set feature that separates the 2nd stage orifice from the seat, like atomics. Those you really should soak pressurized. Otherwise, just do a vacuum test to make sure the dust cap is sealing (I have never had one leak after many years of soaking decades-old regulators) and soak away.

That said, it is convenient to have a tank around the house to check regulators, fill tires. or get a blast of compressed air to clean something. If you're going to use this tank for any diving, I'd suggest a used AL63 or LP72. They're compact, they're cheap, and they're fun to dive with.

Forget about the AL40 as a pony, it's far too big. There are lots of internet divers that seem to think it's a good idea to bring along a spare 40cft of gas of a recreational dive, but I'm certainly not one of them. If a 19cft bottle is not enough to get you out of a tough spot in recreational diving, you are doing something seriously wrong. I'm sure that will not be a popular opinion....

If you are really looking at staged decompression diving in your near future, it's worth getting a 40, but for sure I would look for one used.

 

[Bob DBF]

I'll second getting an old steel 72, for the same reasons that @halocline gave. I've had several given to me because they were gathering dust and the owner heard I was a diver, all are back in service.

As for a pony, you want one that is convenient and easy to use. I got a 19 because I knew a 30 or 40 would get left on the beach due to the hassle, unless I was planning something particularly stupid, at which point I would probably grab a 72 or something larger.


Bob

 

[Diving Dubai]

Forget about the AL40 as a pony, it's far too big. There are lots of internet divers that seem to think it's a good idea to bring along a spare 40cft of gas of a recreational dive

I'll use an English phrase for this. Cobblers!

I've been on a rec dive (planned 30m) with my Al 40 and 15L (HP120?), got smacked by a down current and at the surface had little more than 12cft across both tanks. My wife carries a 12l steel and an AL 30 and had a similar amount of gas left.

On dives in this location now I carry an Al 80 as a pony.

Now granted if your in a benign area with a hard bottom then a 40 might be over kill. but to make blanket statements like you did is disingenuous.

Pick the gear appropriate for the type of diving and the location.

No one after an incident has ever complained that they had too much gas!

 

[Dave Bevan]

My AL40 was exactly the same price as an AL80. Go for something smaller like a dry suit bottle or something.

 

[al303]

#2 for the AL63. While it is useless for a pony, it makes an excellent pool/shallow tank.