O2ptima - BM vs CM?

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inquis

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I'm considering venturing into the CCR realm at some point. Curiosity finally got the better of me, so I decided to solicit experienced opinions on something that's been bugging me for a while about the two current O2ptima configurations. When the CM version is cheaper, seems more stable on a boat (with BM doubles vs the BM O2ptima+sidemounted bailout, or at least equal with Choptima+SM bailout), seems better in caves (lower profile, both with SM bailout), and seems to travel more easily... why would anyone buy the BM version now that the CM is out?
 
The chest clutter is real and might be too much for some people. The chest clutter combined with my already restrictive exposure protection definitely took some getting used to.

Something else to keep in mind is the O2ptima can be converted back and forth between BM and CM so if you’re worried you can get both.
 
I dive and teach on both. I am the minority in that I like the backmount better for deep boat dives. It has a lot to do with comfort, I have been on the backmount unit for nearly a decade, the chest mount for less than two years.
They both work well. The chest mount is much more versatile if you only have one rebreather. It is great for travel, it is light and works with whatever you can get your hands on tank wise at your destination.
The backmount is a workhorse and very intuitive with the IBOV. It is large and heavy for traveling. Much like everything else, there are tradeoffs in every aspect of diving.
Where I have found the chest mount shines is streamlining for very tight wreck penetrations. The backmount with twin 80s is a beast getting through hallways and bulkhead doors. With the choptima, I ditch my deco bottles and can wiggle through anything with my mini doubles. It can also be removed and shoved through an opening to wiggle into a bilge access.
 
What I like about the CM is I can dive any of the exact same OC configs I have been diving for like 20 years and just clip the O2ptima CM to my chest and hook it up to one of my existing tanks and that's it. I've kept my chest clear all these years, not knowing that this is why (but this IS why). It literally interferes with almost nothing. Even the long hose in back mount does not interfere, as long as you bring it across after the Chop is already on. As for the dry suit inflator, it's really no problem at all to stick my hand between the Chop and my chest to operate that. It's no worse than when I used a horse collar BC in my "vintage" configuration.

I really find that the greatest advantage is that if I ever do need to bail out, I'm just going back to any one of the very familiar OC configs I've been using for years. Very comforting. With the BM version, I would be using a brand new and very different equipment configuration that is unfamiliar both on and off the loop. I would find this more stressful under any type of emergency situation.
 
I understand that DiveRite sells a conversion kit. How much is it and how much effort for the CM>BM and BM>CM conversions?
 
I understand that DiveRite sells a conversion kit. How much is it and how much effort for the CM>BM and BM>CM conversions?
I don't know the price off hand, but the effort is no different than building the unit normally. You just swap the head back and forth between the two units. I have separate controllers and huds for mine which makes it even easier.
 
https://www.shearwater.com/products/teric/

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