Independent Doubles

[Eric Sedletzky]

Slinging a 40 or an 80 would seem to be your best bet. it is most like what you are used to.
Breath the back-tank down to 2000, then the slung tank down to 2000, then the back to 1000, then the slung tank to 1000, then the back tank to 500, then the slung tank to 500. or some such strategy. The point is to keep sufficient gas in the tank with the octo (on your back) so your buddy has gas if needed. You will still need a first and second stage with SPG to put on the slung tank.

I suppose it's the same principle but having an 80 slung seems awkward with a single on your back.
I would think there would be balance issues and then you got that big thing under your arm.
Also, he needs to use rental 80's so how would he get one set up quickly and conveniently with the needed bands and clips to set it up as a pony?
I get the picture that he's trying to use plain stock rental AL 80's that they have.

 

[MB NZ]

He could sling a second across his chest (e.g. right hip to left shoulder). OK, it's a cluster**** of gear. Not ideal. but there will be less issues with balance. Alternatively, use trim weights to balance a more traditionally slung cylinder.

 

[tursiops]

I suppose it's the same principle but having an 80 slung seems awkward with a single on your back.
I would think there would be balance issues and then you got that big thing under your arm.
Also, he needs to use rental 80's so how would he get one set up quickly and conveniently with the needed bands and clips to set it up as a pony?
I get the picture that he's trying to use plain stock rental AL 80's that they have.

Very little hardware is needed to sling an AL80. it is not uncommon to do. Cetacea used to make a really nice litle strap, but many are availalbe. All that is really needed is a small cam strap, some paracord, and a couple of bolt snaps.

Added; here is an example of a simple rigging kit:

Stage Bottle Carrier Kit for up to 8 1/2

* Our complete kit comes with the following! ** molded EPDM rubber handle ** Fit any cylinder upto a 8" dia size *** Works great with 8" diameter cylinders with just a little extra length to work with!!*** ** 1 1/4 Stainless steel snaps on each side! ** Stainless steel hose clamp with frabic...

www.piranhadivemfg.com

 

[Badger7]

Personally, I really don't like the idea of carrying an 80 as a stage bottle for an NDL dive. Sounds like either you need to source larger tanks, do less work to consume less gas, or plan shallower and/or shorter dives. If carrying two 80s is truly your only option, yes a more traditional backmount single with a primary and octo and then carry an al80 "slung pony" with a stage/deco reg sounds like you'd get the least amount of liability hassle from your dive operator and concern from your dive buddies.

Dive Rite makes a travel stage kit that just slides over the neck of the tank and locks on with a single cam band. The hose retention bands are even neatly captured by the webbing, so you don't accidently lose pieces when packing/unpacking and switching tanks.

 

[Clernix]

I think where he's going they don't have proper doubles set up, they only offer single 80's so that's why he's trying to figure out how to get more air with what they have.

Correct Eric. I am flying half way around the world so I need a bottom time that makes sense and 80's is all the have.

Sling tank would not be an option. I am carrying a camera/gopro set up. And having the second tank firmly mounted makes more sense for me for a comfort level.

I have experience with doubles but banded. I am concerned with how the tank will move even with two cam straps.

The pieces should all be here within the next 7 days I have a pool session to try it out. I'll post on my thoughts

 

[tursiops]

Correct Eric. I am flying half way around the world so I need a bottom time that makes sense and 80's is all the have.

Sling tank would not be an option. I am carrying a camera/gopro set up. And having the second tank firmly mounted makes more sense for me for a comfort level.

I have experience with doubles but banded. I am concerned with how the tank will move even with two cam straps.

The pieces should all be here within the next 7 days I have a pool session to try it out. I'll post on my thoughts

So, you are experienced with doubles. You are going to be carrying a camera. You have already ordered bits and pieces.
Anything else you haven't disclosed yet?
Why are you even asking questions?

 

[Clernix]

So, you are experienced with doubles. You are going to be carrying a camera. You have already ordered bits and pieces.
Anything else you haven't disclosed yet?
Why are you even asking questions?

The original question was has anyone heard of this type set up? In all my years of diving I have not. I am curious if the tanks will move without the bands or will they sit firm.

I didn't mention the camera because i didn't think it was relevant.

 

[Eric Sedletzky]

The tanks will sit firm if you wet the tank bands first then cinch them down nice and tight.
Remember to that you will have two tanks getting light on you at the end of the dive (aluminum 80's) provided you used up the air so allow for that. You might need to add some additional couple lbs. of weight on your belt.

 

[Eric Sedletzky]

Very little hardware is needed to sling an AL80. it is not uncommon to do. Cetacea used to make a really nice litle strap, but many are availalbe. All that is really needed is a small cam strap, some paracord, and a couple of bolt snaps.

Added; here is an example of a simple rigging kit:

Stage Bottle Carrier Kit for up to 8 1/2

* Our complete kit comes with the following! ** molded EPDM rubber handle ** Fit any cylinder upto a 8" dia size *** Works great with 8" diameter cylinders with just a little extra length to work with!!*** ** 1 1/4 Stainless steel snaps on each side! ** Stainless steel hose clamp with frabic...

www.piranhadivemfg.com

Well that's great, but the OP wants to use independent doubles because the operator only supplies standard AL 80's, and I'm helping him do that. I'm not trying to steer him to some inconvenient and unrealistic setup that he can't use on his trip.

 

[tursiops]

inconvenient and unrealistic setup

Your opinion. I've done it numerous times, and seen it done numerous times. For example, a long dive -- possibly planned deco -- in Bonaire; grap another AL80 and sling it. Takes but moments, works fine.

For the OP, as his actual story and needs/constraints leak out, i really don't care what he does. He has apparently already made his decision based on whatever info he had before he even asked his question here on SB.

The tanks will sit firm if you wet the tank bands first then cinch them down nice and tight.
Remember to that you will have two tanks getting light on you at the end of the dive (aluminum 80's) provided you used up the air so allow for that. You might need to add some additional couple lbs. of weight on your belt.

Would't this tanks get lighter at the end of the dive even if they were steel? You are suggsted he be correctly weighted for his dive and equipment? Yes, I agree. True for any kind of tank, or number of tanks.