OP
So I would have a similar effect that I had with the 119 singles? I do like the 71CF HP tanks
First set of doubles looking for advice
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With these brackets the tanks are not manifolded together so you can still use them as singles and you don't have to buy two more tanks, new valves and a manifold. But you have to switch between regs for gas management. On mine the top of the valves are about even with my shoulders so there low enough for good trim and I don't need to reach the valves because they are totally redundant.
With these brackets the tanks are not manifolded together so you can still use them as singles and you don't have to buy two more tanks, new valves and a manifold. But you have to switch between regs for gas management. On mine the top of the valves are about even with my shoulders so there low enough for good trim and I don't need to reach the valves because they are totally redundant.
I'm exploring this option. Is this the same as the "velcro" bands you have also referred to? How do you have the regs configured? I'm assuming you have a "normal" first stage on one, with spg, octo and second, along with BC/Wing inflator and the other first has only spg and second?
Also, if how do you route and wear your seconds (one for each tank and an octo)?
Or do you dispense completely with the octo, and just have the 2 second stages, one on each tank?
Any pictures?
Thanks!
I have a first stage with a second stage, spg and bc inflator on the left side. Then a first stage with a second stage, spg and a drysuit inflator on the right side. But when I use a 40 on the left side I moved the bc inflator to the right side (80cft tank) so I wouldn't have to keep filling the 40cft tank. I also got lucky that my old regs could be switched to left hand so I switched one of them so now the left side second stage routes over my left shoulder. Here's a couple pics I have downloaded already but I don't have the right side reg mounted. I can post some more pics tomorrow.
Thanks for the response. I am also happy to see that you can use two different size tanks (80 and 40). How does this affect your trim?
So you don't use an "octo"? It looks like you "bungee" one second, do you use a conventional main second (short hose) or do you go with the long hose DIR-style? I was wondering how to keep three seconds sorted. What do you do with the non-bungee'd second while you are using the bungee (in a non-share air situation) when you want to breath down the other tank?
So you don't use an "octo"? It looks like you "bungee" one second, do you use a conventional main second (short hose) or do you go with the long hose DIR-style? I was wondering how to keep three seconds sorted. What do you do with the non-bungee'd second while you are using the bungee (in a non-share air situation) when you want to breath down the other tank?
As far as trim I can't tell any differance between the two differant size tanks. The first time I dove with a 40 and 80 combination I put a 2lb weight in the trim pocket of my bc on the 40 side, and the second time I dove them I forgot to put the weight in and never noticed. The hp 80 is -9lbs full and -3lbs empty and the 40 is -6.3 full and -3.3 empty so in the middle of the dive with a full 40 and half full 80 they are about the same. But I have used my drysuit on all my dives so far this year (water temp still in the low 50's). I have standard (short) hoses and I do have an airsource so I have three second stages, but by switching one of my regs to left hand it's easy to know what reg goes to what tank (hose over my left shoulder goes to left tank and hose over right shoulder goes to right tank, same with the spg's) I made another necklace so when I use two tanks the same size and plan to manage the gas equally in the two tanks I put them both around my neck, It's easy with one reg hose being left handed. One day I forgot both necklaces so I just clipped them off and it worked fine. If I use two 80's or two 40's I will put the bc inflator (with the airsource) on the left side and keep the drysuit inflator on the right side. Here are some more pics.
Thanks for the additional info. So, in the double 80's configuration, you have both primary seconds bungeed and the octo clipped off. And your plan is to donate the octo if anyone need to share air?
Have you tried this with AL80s? When I read the post originally, I thought when you said 80s they are ALs. I'm thinking this would be ideal when I travel, besides at home, where it's easiest to get AL80s. In Bonaire, they have unlimited fills, and I could strap 2 AL80s in easily, without having to put on a manifold which takes considerable time. And, then just swap them out after the dives for full tanks....no need to take the doubles in as a manifold pair for filling.
I can also see this as a benefit when renting tanks too.
I realize that I probably won't get the "hidden" benefit of an extra dive as if they were manifolded together, but air cost is not a major concern when it's included unlimited or only $3 -$5 a tank. And, I plan to get a small compressor in the near future.
Given the above, is there any other down sides to twin versus double tanks?
Thanks!
Have you tried this with AL80s? When I read the post originally, I thought when you said 80s they are ALs. I'm thinking this would be ideal when I travel, besides at home, where it's easiest to get AL80s. In Bonaire, they have unlimited fills, and I could strap 2 AL80s in easily, without having to put on a manifold which takes considerable time. And, then just swap them out after the dives for full tanks....no need to take the doubles in as a manifold pair for filling.
I can also see this as a benefit when renting tanks too.
I realize that I probably won't get the "hidden" benefit of an extra dive as if they were manifolded together, but air cost is not a major concern when it's included unlimited or only $3 -$5 a tank. And, I plan to get a small compressor in the near future.
Given the above, is there any other down sides to twin versus double tanks?
Thanks!
ianr33
Contributor
I have done quite a lot of dives using independant (twin) tanks. My hose set up is exactly the same as it is with manifolded doubles except I add an extra spg on the righthand tank.
This system works GREAT for easy dives on vacation.
The only downsides to independant tanks are:
1) Need to switch regulators to even out the pressure. Doing an OW dive with Al 80's I would probably breathe one down to 1500,switch regs, start ascending when the second tank drops to 1500 and switch back to the first tank when second tank hits 1000. Not a big deal. Just make sure you always have enough gas to do a safe ascent in each tank in the event of a freeflow or other problem. Remembering to switch regs could add to task loading issues on a stressful dive
2) If you do have to shut down a tank then you have just lost access to maybe half you gas.With manifolded doubles you would still have access to all of it. Again not a big problem on NDL or limited limited deco dives.
For technical dives with significant deco and a buddy I prefer manifolded doubles.
For long solo dives in the Caribbean I would choose the independant set up
This system works GREAT for easy dives on vacation.
The only downsides to independant tanks are:
1) Need to switch regulators to even out the pressure. Doing an OW dive with Al 80's I would probably breathe one down to 1500,switch regs, start ascending when the second tank drops to 1500 and switch back to the first tank when second tank hits 1000. Not a big deal. Just make sure you always have enough gas to do a safe ascent in each tank in the event of a freeflow or other problem. Remembering to switch regs could add to task loading issues on a stressful dive
2) If you do have to shut down a tank then you have just lost access to maybe half you gas.With manifolded doubles you would still have access to all of it. Again not a big problem on NDL or limited limited deco dives.
For technical dives with significant deco and a buddy I prefer manifolded doubles.
For long solo dives in the Caribbean I would choose the independant set up
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