Friends don't let friends dive ring bungees.
In my experience there are a couple problems with ring bungees.
1) Bungee is by necessity short and has limited ability to pull the tank up where it needs to be.
2) The bolt snap and quick link used to connect the ring to the shoulder D-ring also prevents the tank from riding up where it needs to be.
The end result is 'low mount' not 'side mount'.
The arguments are always "they are easy to put on" and " I can carry my tanks out of the water with them". The truth is that they are not that much easier to put on, and it comes at the cost of proper streamlining in the water. And you can also carry your tanks out of the water with a loop bungee system if you just use a loop of paracord and a bolt snap around the tank valve.
The advantage of a continuous loop bungee is that the bungee is much longer and stretches much farther, so that it is both easy to put on and pulls the tanks up behind the arm pits where they belong. If you use a bolt snap and paracord loop around the valve, you can connect the bolt snaps to the shoulder D rings and let the paracord support the tank, when you first get in the water, or while walking to or from the water with the tanks attached. Just be sure to leave them long enough to let the tank ride up behind the arm pit. You'll find this length is a lot longer than the hardware on a ring bungee set up.
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You can also use a ring on a continuous loop bungee if that trips your trigger. For example I use a continuous loop bungee with my Sidekick CCR. I run the bungee through a ring on the CCR side and use the ring as the attachment for the bolt snap on the CCR. I also run a loop of paracord from the ring through the webbing triglide for the shoulder D-ring, ensuring that I leave it long enough to let the CCR ride up behind my arm pit. The paracord then supports the CCR out of the water. Once in the water, I pull all the slack out of the bungee on the other side, which pulls the CCR up tight, then use this slack to loop around the tank valve knob, and the tank then keeps the CCR snug. I also have a paracord loop and bolt snap on the tank side and secure the tank to the shoulder D-ring as soon as I get in the water, so the tank won't go anywhere until I complete the connections and loop the bungee over the valve. it also supports the tank out of the water if I walk the rig in or out of the water.
In other words, I have continuous bungee, with a ring on one side, a loop on the other and the ability to carry the tanks out of the, with redundancy if the bungee breaks. There is also no hard connection, so a stuck bolt snap is not a potential problem.
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If you want to do that OC, then use a ring on each end of the continuous loop bungee and use your normal chokers to connect the bungee to the tanks. Just back stop it with bolt snaps on paracord loops around the tank valves to give you the ability to carry the tanks connected out of the water. You'll still have "easy to put on" and "carry my tanks out of the water" but you'll have it with tanks that are properly positioned and trimmed.
