Good first post... I think there is enough information here so you can acheive your goal of being a human popsicle 
How to setup a Double Tank rig?
- Thread starter BlueWater Diver
- Start date
Please register or login
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
- Ability to post and comment on topics and discussions.
- A Free photo gallery to share your dive photos with the world.
- You can make this box go away
Then there's no way in hell I'm going to recommend that you try diving doubles.
Scuba is expensive. Get used to it.
elan
Contributor
I think the legendary Uncle Pug had a nice thread about this once upon a time (probably gone in one of the crashes).
All connections in scuba are potential failure points. In a single tank rig, you have the tank o-ring, the DIN or yoke o-ring, the internal workings of your first stage, the port plugs and hoses coming off the first stage, and the connections into the second stage. In doubles, you add a second tank o-ring, a second first stage, more port plugs, manifold o-rings, and a second valve and isolator. Although the majority of these will never fail, and if they do, are unlikely to fail in a catastrophic fashion, one can get leaks, and the more connections, the more possibilities. That's why a lot of the training for the use of double tanks involves learning to control leaks. This involves shutting valves -- which may shut the gas supply off to one set of regulators, or may simply isolate the two tanks into amounts to two singles.
I'll bet just about everybody here who dives double tanks has, at one time or another, either shut off all his gas supply, or at least shut off the gas he was breathing by mistake (or his buddy has done it). It is not a big deal if you are good at valve manipulation, AND if you stay calm. It could very easily panic somebody who had no training and hadn't experienced running out of gas since his tank was turned off in open water class.
To dive doubles WITHOUT knowing how to manipulate valves is just to dive a huge single tank with a bunch more failure points. You're probably safer with a larger, single tank (which was the point of UP's thread). So, if you do decide to use doubles, please get some training in how to use them. Manipulating valves while remaining at depth, in position, and cognizant of where your buddies are and what is going on around you usually takes quite a bit of practice. If you have difficulties with these things in a single tank, as many newer divers do, those difficulties will simply be multiplied.
It is my personal opinion, from watching people come up the training path behind me, that time spent mastering buoyancy and increasing tolerance for task-loading in a single tank results in a much smoother transition to doubles, and better technique in them comes more quickly that way. I do not believe doubles are a good solution for novice divers with gas consumption issues. Addressing the technique problems that lead to high consumption is far more productive, and if necessary, acquiring a larger single tank is an easy thing to do. You can get a larger tank AND take a class like Fundies, Essentials, or Intro to Tech for the cost of a nice set of doubles and another regulator
All connections in scuba are potential failure points. In a single tank rig, you have the tank o-ring, the DIN or yoke o-ring, the internal workings of your first stage, the port plugs and hoses coming off the first stage, and the connections into the second stage. In doubles, you add a second tank o-ring, a second first stage, more port plugs, manifold o-rings, and a second valve and isolator. Although the majority of these will never fail, and if they do, are unlikely to fail in a catastrophic fashion, one can get leaks, and the more connections, the more possibilities. That's why a lot of the training for the use of double tanks involves learning to control leaks. This involves shutting valves -- which may shut the gas supply off to one set of regulators, or may simply isolate the two tanks into amounts to two singles.
I'll bet just about everybody here who dives double tanks has, at one time or another, either shut off all his gas supply, or at least shut off the gas he was breathing by mistake (or his buddy has done it). It is not a big deal if you are good at valve manipulation, AND if you stay calm. It could very easily panic somebody who had no training and hadn't experienced running out of gas since his tank was turned off in open water class.
To dive doubles WITHOUT knowing how to manipulate valves is just to dive a huge single tank with a bunch more failure points. You're probably safer with a larger, single tank (which was the point of UP's thread). So, if you do decide to use doubles, please get some training in how to use them. Manipulating valves while remaining at depth, in position, and cognizant of where your buddies are and what is going on around you usually takes quite a bit of practice. If you have difficulties with these things in a single tank, as many newer divers do, those difficulties will simply be multiplied.
It is my personal opinion, from watching people come up the training path behind me, that time spent mastering buoyancy and increasing tolerance for task-loading in a single tank results in a much smoother transition to doubles, and better technique in them comes more quickly that way. I do not believe doubles are a good solution for novice divers with gas consumption issues. Addressing the technique problems that lead to high consumption is far more productive, and if necessary, acquiring a larger single tank is an easy thing to do. You can get a larger tank AND take a class like Fundies, Essentials, or Intro to Tech for the cost of a nice set of doubles and another regulator
crpntr133
lost, even with a compass
Diving doubles isn't rocket science but if you don't know what you are doing you can get in trouble real fast. I've told my story too many times so here is the abbreviated version. LEARN TO DO VALVE DRILLS FIRST!!!! If you can't do a valve drill with doubles then hang it up. You can get yourself in troubles real fast, take my word for it.
As far as the $$ is concerned. You will basically buy a whole new set up and add your old gear to it. Minus the BC that will be replaced with a plate and wing. Buy a 130 and be done with it. Personally I wouldn't dive doubles in a wetsuit either but that is another thread.
Ya doubles are cool to look at but diving isn't about being cool. It's about knowing how to get your a$$ out of trouble underwater and looking cool afterwards.
As far as the $$ is concerned. You will basically buy a whole new set up and add your old gear to it. Minus the BC that will be replaced with a plate and wing. Buy a 130 and be done with it. Personally I wouldn't dive doubles in a wetsuit either but that is another thread.
Ya doubles are cool to look at but diving isn't about being cool. It's about knowing how to get your a$$ out of trouble underwater and looking cool afterwards.
elan
Contributor
I might be wrong but just learning how to close the manifold valve will give a great improvement over the single tank.
Anti-Hero
Contributor
Close the manifold? The manifold consists of 3 valves which may or may not need to be closed at any given time. Closing the isolator only allows access to 1/2 the available gas, which after a long/deep/both dive may not be sufficient. Quickly identifying the problem and closing the *CORRECT* post is the best solution.
ShakaZulu
Contributor
Looks like you guys scared the OP away!
This was a pretty tough room to be sure.
crpntr133
lost, even with a compass
Always seems that we are the bad guys. But lets face it we are talking from experience.
Similar threads
