Attaching a second tank

[Rick Inman]

What is the best way to rig these up so that they a)don't fall off! b)allow for easy movement while walking and swimming and c)don't drag all over this gorgeous reef.

Here's the thing. What happens sometimes is that the questions themselves expose that you should not attempt this, should you wish to do the dive safely. It's like if someone came up and asked you, "Hey, I have this old scuba tank and regulator and I've never dived, but I'd like to try it. How do you screw this regulator thing into tank?" The question itself tells you that the person should not be diving and needs formal instruction. Not a lesson on the internet.

If the dive site is a long swim out, why not do a surface swim and drop down, then surface swim back? If the site is a doubles dive, then get doubles training and make the dive. A person with training that would include stage rigging, stage deployment and stage gas management planning wouldn't do this dive that way anyway. They'd just use their doubles.

That's simply MHO.

 

[k-valve]

Guys, I see where you're coming from, but how about just spitting it out rather than alluding to it?


OP, it sounds like you may not have have the experience to be doing what you're considering safely - there's more to twin tank diving than having two tanks/regs

Someone suggested a try-out first, that's good advice IMHO

Agreed...100%. I'm wondering if the OP has thought about what he's going to do with that extra tank besides use it to swim out to the site. Is it just for safety or is he planning to use the gas as part of the actual dive. If he's using it for part of the dive has he thought that through...potential for deco obligations and off-gassing for example? Maybe the guy just wants to sit at 30' taking pictures for an extended period of time. Nothing wrong with that I suppose, but there certainly is potential for the OP to get himself into BIG trouble if he's not properly trained and he builds up some deco obligations or is diving to a depth that could get him into trouble. That part seems pretty evident. I can see him wanting to make the swim to the site underwater if he's going to be in rough water, but not if he's planning on dropping down to any kind of depth.

I guess I'd like to hear more from the OP about the dive profile and what he's planning to do with that extra tank.

 

[cwkline]

I offered some assistance but apparently the OP is declining. I guess it is a super secret reef? Good luck with the dive and hope all turns out well for you.
Charlie

 

[SDAnderson]

What is the best way to rig these up so that they
a)don't fall off!
b)allow for easy movement while walking and swimming and
c)don't drag all over this gorgeous reef.

Best option: set up as doubles.
Alternative: stage rig one and clip it to your harness.​

I have an Oceanic vest style BC to attach it to with plastic D-clips.

Uh, oh. You might be able to make it work (i.e., survive) but this BCD was never intended to be used for the kind of dive you are thinking about and isn't really suitable.​

I have two tanks. I have two regulators. And I know of a dive that is supposed to be gorgeous but is one heck of a swim from the entry. I would like to take two tanks down with me rigged and ready, but I have never carried stage bottles with me.

Without the training and experience, the dive you are hoping to do is potentially extremely dangerous. The most important piece of gear in your inventory is your brain: use it. The internet is not the place to learn about diving beyond recreational limits and using doubles/stage rigs. Find an instructor who is doing the kind of diving you are contemplating and learn about extended range or decompression diving.​

 

[Reg Braithwaite]

Guys, I see where you're coming from, but how about just spitting it out rather than alluding to it?

If "it" is the suggestion that people should not learn to dive on the internet, what the bleep do I know that I should tell someone else how to learn and what risks they should choose to take? I'm a huge fan of informed choice. What I hope the internet can help teach is what risks are involved so that the OP can make informed choices about whether to do this dive, what type of training, practice, instruction, or research to perform before doing this dive, with whom to do this dive, and finally how to gear up for said dive.

I personally know close to squat about diving side mounted, diving with a bottom stage, diving independent doubles, or manifolded doubles. But I do know a few questions that come to mind, and I shared them. I figured that no matter how embarassingly unqualified I am to make a dive like this, sharing some of the questions that come to mind would be unlikely to mislead the OP.

 

[smellzlikefish]

Wow, touchy subject.

My question is simple; what is the best way to rig it. As far as safety goes, the risks I am assuming, as I see it, are as follows:

1) Extra time down= extra nitrogen buildup. This can be solved by staying at 40 feet, which was the plan to begin with. Save extra air anyway. I have made and am very familiar with deco stops. This is not going to be a deco dive.

2) Worst case scenario is the extra tank breaks loose. If I breathe off of this rigged tank first, I have a backup in case anything goes awry. If for some reason I lose it, I'm out a reg and a tank, but I'm still okay.

3) Training- no, I am not a technical diver. Classes cost money, and even if my computer goes out, I still understand the dive tables I carry on my person inside and out.

Beyond this, I cant think of many circumstances that would get me into serious trouble and certainly none that would get me in over my head. Am I missing anything critical?

 

[Dtaine]

...
2) Worst case scenario is the extra tank breaks loose. If I breathe off of this rigged tank first, I have a backup in case anything goes awry. If for some reason I lose it, I'm out a reg and a tank, but I'm still okay.

I definitely wouldn't call that the "worst case" scenario, but losing a tank and a reg would still suck.

I recently got a 40 cf tank which will later serve as a stage bottle, but I also have a setup that works perfectly with the tank added (bp/w). For now I'm slinging it just to get used to it being there (and working with it).

I'm assuming your bcd has plastic d-rings where you could sling the tank, the problem is, as others have mentioned is that the bcd you have now really isn't meant to handle stage bottles. Is it possible you could make it work? Sure, perhaps, but that dive will go a whole lot smoother if you're setup correctly w/ a bcd that's made to handle the extra equipment.

 

[shellbackdiver1]

Am I missing anything critical?

Sounds like a great plan. Good luck with that.

 

[Rick Inman]

If I breathe off of this rigged tank first...

You say, "If" you breathe off it first. Sounds like you're not sure what the correct proceedure is on this.

If you do breathe from the pony first, when would you switch to your backgas?

 

[Mike Edmonston]

I have two tanks. I have two regulators. And I know of a dive that is supposed to be gorgeous but is one heck of a swim from the entry. I would like to take two tanks down with me rigged and ready, but I have never carried stage bottles with me. What is the best way to rig these up so that they a)don't fall off! b)allow for easy movement while walking and swimming and c)don't drag all over this gorgeous reef. I have an Oceanic vest style BC to attach it to with plastic D-clips. Any ideas?

If you are trying to beat the surf, and not get your butt handed to you by crashing waves, then "Travel gas" could be the way to get to your site of choice, and still have enough remaining gas for the dive itself.

For the sake of giving you a civilized answer, I will assume 4 things.

1. You're NOT exceeding your NDL's. (NO DECO!!)
2. You're NOT exceeding recreational depths 130'.
3. YOU HAVE A BUDDY!!!!
4. You have a DIVE FLAG!!!!

If you are following the above 4 sentences, then read on. If not then you should probably be watching this: YouTube - Barney Campfire Sing-Along Part 1

1. Use an 80cf tank with stage rigging and a single second stage and an spg. Don't need an octo on a stage. Clip it to your chest D-ring (you should have 1) and a waist D-ring on your left. If you don't have a waist D-ring, a weight belt (2" web) with a D-ring on it could do in a pinch. Make sure it doesn't slide around.

2. Breathe off your stage, and keep your depth to 15' MAX, on the swim out there. Use a compass.

3. Once at your little secret reef, REMOVE your stage, and clip it off to your dive flag or flag line. Your cylinder should be buoyant by now anyway, so you won't lose it on the pretty reef!

4. Dive the reef on your BACKGAS only. Again, refer to the 4 guidelines I posted above.

5. Do not use the stage to increase your bottom time... Oh wait... You did clip it off to the flag, right???

6. Post your unequaled success on Scubaboard and be prepared to be hammered by the Tech Diving Masses.

Have a nice dive......