My AN/DP/Helitrox course
- Thread starter Marie13
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Along the Red Sea coast of Saudi Arabia it comes down to logistics. AL40s simply aren’t readily available leaving AL80s as the only real choice.
Shops can be unreliable about their gas on hand and having the only qualified filler at work that day. The work ethic is quite different here.
Shore dives from uncontrolled locations raise suspicions of the border guard thus forcing divers to dive resorts that are access controlled. Many resorts don’t have anything but 21% and charge you for bringing in your own tanks.
So, I could wait around for the next year until a shop gets in some AL40s and I could rack up a ton of pay-per-use fees bringing in a smaller deco tank every time I want to dive. However, if the AL40 proponents were here in Saudi Arabia, I’m betting they’d learn to get their fills in an AL80 when they can, to get three or four dives from it and to handle an AL80 like everybody else has.
Also, I don’t think an AL80 is so heavy to be any more burdensome than everything else we do as divers.
Shops can be unreliable about their gas on hand and having the only qualified filler at work that day. The work ethic is quite different here.
Shore dives from uncontrolled locations raise suspicions of the border guard thus forcing divers to dive resorts that are access controlled. Many resorts don’t have anything but 21% and charge you for bringing in your own tanks.
So, I could wait around for the next year until a shop gets in some AL40s and I could rack up a ton of pay-per-use fees bringing in a smaller deco tank every time I want to dive. However, if the AL40 proponents were here in Saudi Arabia, I’m betting they’d learn to get their fills in an AL80 when they can, to get three or four dives from it and to handle an AL80 like everybody else has.
Also, I don’t think an AL80 is so heavy to be any more burdensome than everything else we do as divers.
If I were forced to use 80s I wouldn't get it filled all the way honestly. I dont need 2.5 hrs of O2 in the ocean
I’m not communicating this very well. It’s not about how much deco gas I need but about the logistics of getting the gas and having to pay again just to have the gas on hand.
When the qualified attendant is on duty (unpredictable at best) at the only two shops that have O2, it makes more sense and it’s much cheaper to fill an AL80 full and leave it at the resort for three to four dives than underfill, dive with it, take it out of the resort, pay for another half fill and then pay again to bring the tank back into the resort. Again, it’s about pre-splash logistics and not about the deco obligation during the dive.
If someone has the time and money to line up smaller bottles and pay every time they want to use It, then they’re probably retired, got lucky when a shop happened to have an AL40 in stock and landed a more lucrative career than I’ve had.
I’m satisfied other much more seasoned technical divers than me have thought this through and I’m willing to roll with their technique.
When the qualified attendant is on duty (unpredictable at best) at the only two shops that have O2, it makes more sense and it’s much cheaper to fill an AL80 full and leave it at the resort for three to four dives than underfill, dive with it, take it out of the resort, pay for another half fill and then pay again to bring the tank back into the resort. Again, it’s about pre-splash logistics and not about the deco obligation during the dive.
If someone has the time and money to line up smaller bottles and pay every time they want to use It, then they’re probably retired, got lucky when a shop happened to have an AL40 in stock and landed a more lucrative career than I’ve had.
I’m satisfied other much more seasoned technical divers than me have thought this through and I’m willing to roll with their technique.
Same thing here in a sense. Ten bucks or something to fill a 40, fill it once and and top it off till the % gets too low.
I just do a quick plan to see where my limits are at before diving, seem to never breathe more than 1000psi off a tank so you can top them a few times before refilling.
It’d be nice to use standard gases so that you know this or that but doing a quick plan is what we should be doing anyways. It works for the way we dive here....
I just do a quick plan to see where my limits are at before diving, seem to never breathe more than 1000psi off a tank so you can top them a few times before refilling.
It’d be nice to use standard gases so that you know this or that but doing a quick plan is what we should be doing anyways. It works for the way we dive here....
One option you're forgetting is the AL72. I know that they're not super common but I do know quite a few dive shops that are starting to carry them or can order them.
Slightly smaller diameter than an AL80 (6.89" vs 7.25"). They trim out like AL40s for me. According to DGX the Metal Impact version is 0.7 Full : + 2.8 Empty (with a valve). Compare that to an AL40 and buoyancy characteristics while full are very similar.
I have two of them I use for 32% for ocean bailouts/stages. I basically treat them like AL80s. I honestly haven't really thought of using them for O2 since an AL40 can cover me for 45 minutes+ at 20ft (6m) but I guess if someone was ordering them new and had a desire to need more O2 than a AL40 provides they could be a better suited option than an AL80.
I agree with others that I would much rather carry an AL40 for O2. I haven't ever used an AL7 (7 Liter) but I assume they would be similar. Otherwise I'd happily dive an AL80 filled to around 130-140 bar (~1800-2000psi) for O2. It won't feel like a boat anchor on my side.
I found the comments about Ali80's interesting.
When I originally started carrying stages in the 90's they where steel, which are a bitch (and usual practice at the time in the UK). Using Ali' stages in the South China seas was a revelation.
When I qualified on CCR, over 16 years ago. It became apparent that I would need to carry a stage, both for myself, but more importantly for my OC buddies. The buoyancy issues of steel stages whilst manageable (although far from ideal) on OC, are totally impractical when using a CCR. So I invested in an Ali80. Probably 90% of my dives since then have meant I have been carrying an Ali80 for bailout. I don't really notice it other than the faff when kitting up on a boat, and dekitting on the boat.
My stand kit is CCR, Ali80 and camera.
Even last week on OC, I carried an Ali80 for the second dive. Having done over an hour on the first dive, the twins where a little low for the second. I used my CCR bailout as primary gas for the first section of the OC dive, then switched back to the back gas at then end.
Granted, I don't do caves, and I don't swim fast.
When I originally started carrying stages in the 90's they where steel, which are a bitch (and usual practice at the time in the UK). Using Ali' stages in the South China seas was a revelation.
When I qualified on CCR, over 16 years ago. It became apparent that I would need to carry a stage, both for myself, but more importantly for my OC buddies. The buoyancy issues of steel stages whilst manageable (although far from ideal) on OC, are totally impractical when using a CCR. So I invested in an Ali80. Probably 90% of my dives since then have meant I have been carrying an Ali80 for bailout. I don't really notice it other than the faff when kitting up on a boat, and dekitting on the boat.
My stand kit is CCR, Ali80 and camera.
Even last week on OC, I carried an Ali80 for the second dive. Having done over an hour on the first dive, the twins where a little low for the second. I used my CCR bailout as primary gas for the first section of the OC dive, then switched back to the back gas at then end.
Granted, I don't do caves, and I don't swim fast.
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