2 AL80 as doubles...cold water diving.

[rjgiddings]

Anybody here use twin AL80's as their doubles air supply?

I'm curious what you did/ didn't like about it ?

Thanks!

 

[rhwestfall]

If I require a dry suit for the dive, it is steel tanks.... I have a set of AL80s for when I am in a wet suit (water in the mid 70's or above at depth, and no long deco). It is mostly about the required weighting, and achieving a balanced rig.


YMMV

 

[tbone1004]

they're common in warm water climates where they are needed for lack of negative ballast. I don't personally like them and if I need that kind of volume in doubles would much rather use lp72's.
In your neck of the woods they're going to require a lot of lead, about 10lbs more than their steel equivalents which is enough for me to say avoid them

I assume you're looking at the set on seattles craigslist. The price they are asking is pretty good for a set of doubles with bp/w. If you have steel tanks already that are 7.25" you can swap those over and take the AL's out.

Down where I am, the kind of general rule is about $250 for a set of AL doubles, and about $400 for a set of steel doubles. In that case, the craigslist ad would have you at $150 for the bp/w which is a good deal.

 

[Divin'Papaw]

I started my diving in the Great Lakes area but now live in South Florida. Up north, the vast majority of doubles divers use steels for the reasons already stated above. Down here in South Florida, a healthy majority of doubles divers I see are using double AL80s. If you are diving where a drysuit and thick undergarments are required, double AL80s make little sense. You've got to added ~10 pounds to your rig just to counteract the buoyancy of the tanks. Down here is South Florida you run into the opposite issue. Diving heavy steel doubles in a thin wetsuit leads to issues of being too heavy and you need to work through what redundant buoyancy options you have available.

 

[Lorenzoid]

Hoosier explained it well. The rule of thumb seems to be steel tanks for cold water, aluminum for warm water (like S. Florida warm). For the thick wetsuit or drysuit you need for Seattle water, you'd probably need to carry an uncomfortable amount of lead without the help of steel tanks.

 

[CptTightPants21]

Weighting and geography issues aside, it depends on what kind of diving you plan on doing. Double 80s simply don't provide enough gas for the type of diving I am doing. Unless it's something shallow like Mexican caves, my preference will always be for steel doubles. HP100s and LP85s for "smaller dives", HP120s and LP108s for the "bigger dives"

 

[Jack Hammer]

Aluminum doubles are great in warm water, not so much in cold water. As mentioned above, for deeper dives they limit your time quite a bit.

 

[rjgiddings]

Yeah. I'm diving cold, Puget Sound waters. Yes, you FL folks make me a bit jealous. But these responses are all great - and really where my head was to begin with... did I wanna add more lead to offset the buoyancy...hmmm. Nah !

I currently have two faber 95 steel tanks ...I could just double them up and voila. I'm now imagining what sort of beast that would look like on my back.

 

[Doby45]

Yeah. I'm diving cold, Puget Sound waters. Yes, you FL folks make me a bit jealous. But these responses are all great - and really where my head was to begin with... did I wanna add more lead to offset the buoyancy...hmmm. Nah !

I currently have two faber 95 steel tanks ...I could just double them up and voila. I'm now imagining what sort of beast that would look like on my back.

It is actually not bad. Now two 104/108s doubled is something else.

 

[tbone1004]

It is actually not bad. Now two 104/108s doubled is something else.

lp121's.... properly terrible, from experience