I have done more than 20 cave dives in Mexico with double AL 80s, and I felt good about the trim the entire time. Of course, I never finished a dive with less than a third of my gas.
AL80 Doubles...Worth It???
- Thread starter Michael Guerrero
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I have done more than 20 cave dives in Mexico with double AL 80s, and I felt good about the trim the entire time. Of course, I never finished a dive with less than a third of my gas.
Xaryo
Contributor
Most of my "normal" diving, including most of my tech diving is done wirh double al80. Wet and dry summer and winter. I use a v-weight of 15 # to neutralise the buoyancy of emptying tanks.
If i need more gas i'll simply sling 1 or 2 stages.
For really big dive, i'll use the big bertha of a double 130 otherwise, no need to demolish my back hauling that much weight.
Al80 (or LP85) for the win!
If i need more gas i'll simply sling 1 or 2 stages.
For really big dive, i'll use the big bertha of a double 130 otherwise, no need to demolish my back hauling that much weight.
Al80 (or LP85) for the win!
When I was diving back mounted twins, the alu 80s were awesome. With a v weight with a tail the trim was fine.....using HP100s in BM, were just too short, they didn't trim out nice at all. Alu 80s are great versatile tanks.
Twin AL80s are wonderful.
They're cheap, light and easy to maintain. They are a fraction of the cost of steel tanks. You can ride them hard and put them away wet with little consequence. And I can pick them up and toss them around with ease (I have to use a dolly to move my twin steel 130s). Furthermore, it's a lot easier to get used to diving with doubles with AL80s than with heavier steel sets.
Twin AL80s are a great choice for tech diving in the ocean diving in a wetsuit.
Twin AL80s are great for your first set of doubles. What's the worst case scenario? You break them up and use them as individual AL80s. Or you sell the $80 tanks for $60 and put the money towards $400 steel tanks.
They're cheap, light and easy to maintain. They are a fraction of the cost of steel tanks. You can ride them hard and put them away wet with little consequence. And I can pick them up and toss them around with ease (I have to use a dolly to move my twin steel 130s). Furthermore, it's a lot easier to get used to diving with doubles with AL80s than with heavier steel sets.
Twin AL80s are a great choice for tech diving in the ocean diving in a wetsuit.
Twin AL80s are great for your first set of doubles. What's the worst case scenario? You break them up and use them as individual AL80s. Or you sell the $80 tanks for $60 and put the money towards $400 steel tanks.
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I was thinking about making my AL 63s into a small twinset. Any thoughts on this for a petite woman, good on gas to learn to use twins?
I also have HP 80s but they seem so heavy. I'm thinking I'll probably end up doing SM but I'd like to at least try to do twins. I may just rent a doubles setup a few times to see how it goes,too. I'll most likely do a Fundies class in a single setup, then see how it goes from there.
I also have HP 80s but they seem so heavy. I'm thinking I'll probably end up doing SM but I'd like to at least try to do twins. I may just rent a doubles setup a few times to see how it goes,too. I'll most likely do a Fundies class in a single setup, then see how it goes from there.
I think it's always easier to learn doubles with whatever is manageable for you. It that means AL63s, then that's fine.
The issue that you are going to eventually run into with small tanks is gas matching - "thirds" will be probably be based on your tanks - 42 cubic feet. If you were diving with me, and I had my steel 130s, I'd hit turn pressure at 2,900 PSI. That makes for a rather short dive.
So unless you only dive with other petite divers, at some point you're gonna have to start using the bigger tanks.
Diving wet, I wouldn't consider anything other than al80s. In a 3mm suit with a steel plate I don't need any weight at all, even with a couple of al80 slings at low pressures, and I can swim the whole lot to the surface if I have to. I've used heavier cylinders, and it's not safe with a wetsuit - I had a wing failure and really struggled to keep my rig at the surface until I could get it up onto the boat. Different story with a dry suit, obviously.
I've never noticed twinned 80s going 'butt-light', although most of my profiles are 160-200 feet for 20-30 minutes, so my back-gas (assuming I start with full tanks) rarely gets much below half full. With the amount and weight of crap you're carrying for deep wreck penetration, a couple of pounds' buoyancy change here or there is unlikely to make much difference...
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I've never noticed twinned 80s going 'butt-light', although most of my profiles are 160-200 feet for 20-30 minutes, so my back-gas (assuming I start with full tanks) rarely gets much below half full. With the amount and weight of crap you're carrying for deep wreck penetration, a couple of pounds' buoyancy change here or there is unlikely to make much difference...
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Michael Guerrero
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Thanks. I'm thinking about some LP85s too. They are slightly less buoyant empty, but should work well.
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I do most of my open water tech in 80s. They are great wet. Im not an avocate of steel tanks and wetsuits so if I need more gas then I normally add a stage.
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