Independent Doubles

[Clernix]

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.

Thank you Eric that is the information I was after. One of my concerns is emptying the tanks evenly for trim but honestly I am not the most trimmed diver in the group. Going to overweight the first couple dives and work backwards on the amount of weight.

I also know myself when I dive Borneo/Indonesia. Its hard to stay focused when you are surrounded by beauty of the reef.

 

[paddydiver]

Surely the shop can pull a 15l tank from somewhere? Everything else sounds like a total mess for a diving holiday. You're diving in tropical water in a thin wetsuit carrying 2 regs 2 tanks that you have to remember to breathe evenly from...and a camera.....and you want to dive over weighted for the first few??!!! Whats the lift capacity of your BCD? Is it a wing for doubles?

 

[Clernix]

Surely the shop can pull a 15l tank from somewhere? Everything else sounds like a total mess for a diving holiday. You're diving in tropical water in a thin wetsuit carrying 2 regs 2 tanks that you have to remember to breathe evenly from...and a camera.....and you want to dive over weighted for the first few??!!! Whats the lift capacity of your BCD? Is it a wing for doubles?

If they could scrounge up a 15L they would I am told. I don't foresee the set up being that big of an issue. If the two octo's are secured it will make for a trim set up.

I'm not to worried about breathing evenly if one tank goes down a couple psi more no issue. The tanks will be weighted.

As far as the lift on the wing its 45lbs but remember the Al 80's will both be positively buoyant towards the end of the dive.

The more I talk about the set up the more I see the advantages. As I mentioned a lot of times I get distracted by the wonders around me. So even if I could get a 100 or 120 tank I really wouldn't mind carrying an 80 as a reserve tank.

 

[tursiops]

The tanks will be weighted.

What does this mean?

the Al 80's will both be positively buoyant towards the end of the dive.

But above you say they will be weighted, whatever that means.
You actually think you will be using that much gas? If so, then the 100 or 120 you are seeking won't be enough.

The more you talk about this the bigger cluster it appears to be.

 

[rjack321]

As far as the lift on the wing its 45lbs but remember the Al 80's will both be positively buoyant towards the end of the dive.

Is it a single tank wing or actually made for doubles - cause those are two different things despite both being "45lbs"

The more I talk about the set up the more I see the advantages. As I mentioned a lot of times I get distracted by the wonders around me. So even if I could get a 100 or 120 tank I really wouldn't mind carrying an 80 as a reserve tank.

You don't know what you don't know, and neither does your destination... Independent doubles fell out of favor decades ago for a reason and the 4 regulator requirement is a mess.

And what do you need 200cf of gas for? If your consumption is that high leave the camera behind and spend the trip getting comfortable in the water.

 

[inquis]

remember the Al 80's will both be positively buoyant towards the end of the dive.

Not with regs and bands and more than 500 psi /35 bar of gas remaining in each.

 

[Eric Sedletzky]

Thank you Eric that is the information I was after. One of my concerns is emptying the tanks evenly for trim but honestly I am not the most trimmed diver in the group. Going to overweight the first couple dives and work backwards on the amount of weight.

I also know myself when I dive Borneo/Indonesia. Its hard to stay focused when you are surrounded by beauty of the reef.

Draw them down 500 psi at a time.
Figure out which second stages you want where and remember your setup. For me I would run the left tank on a bungeed second stage under my chin and the right tank I'd have a standard setup like a 32" and a 40" octo (the 40" for your OOA buddy). Use the 32" and the bungeed second for yourself. You'll need to figure out how to secure the 32" (right side) when you're on your left tank.
Don't dive overweighted please. You should be neutral at the end of the dive at 15' on reserve pressure (in both tanks) and you should be able to hold a safety stop with no air in your wing. You said you have a BP/W, and I'm assuming you also have a doubles wing right? I hope so.
If you're using two floaty tanks like 80's then add three lbs. to your normal single tank setup.
If you were using two tanks that end up perfectly neutral then nothing changes. If you were using two negatively buoyant tanks then you have to remove some weight to allow for that.
Please pay attentiin to what you're doing. Concentrate on your gear and dive/air management first then get carried away with all the beautiful scenery. That's how divers go OOA.
That's akin to taking your eyes off the road while driving to look at all the breathtaking scenery and rear ending someone.
To be honest, skip the camera on your first few dives to see how it goes.

This setup is kind of a CF but if that's the only option you have then I wish you the best of luck.
You can make it work.
Stay safe!

 

[Clernix]

The tanks will be weighted means I will have tank weights on them sorry I should have been more clear. It will help a little if one tank is emptier.

Interesting that independent doubles have fallen out of favor. I had never heard of them hence the post. I have been diving for 40 years and I had never heard of them. BUT I only dive marine parks overseas so a lot of the divers don't even have their own gear.

the wing is designed for doubles. I would not use 200cf of gas. But I do tend to create a large distance between me and the group depending on the guide's comfort level. I have always wanted to carry a pony tank but my bags are full as it is.

 

[happy-diver]

I think you need to add a few more tools to your dive shed chief
and listen less to what you think, and more to what others know

 

[divezonescuba]

If the shop does not require four second stages for sidemount divers, they should not require four from an independent backmount diver.

If they don't know what sidemount diving is, the shop manager should make an effort to find out.

But, I think it is really more of a case of miscommunication than ignorance.