Revo or Optima?

[kensuf]

ok I'll bite .... take me down the rabbit hole Alice .... how do they measure WOB for CE. Upright, in trim, inverted and take average? ..... Ohh I see, I need a physics degree to interpret the results DV OR respiratory pdf

It's measured in different angles. There was a very clear warning in the JJ user manual that trying to breath from the unit while inverted would leave the diver less than happy and that it did not pass the CE test in that particular orientation.

 

[Jack Hammer]

It's measured in different angles. There was a very clear warning in the JJ user manual that trying to breath from the unit while inverted would leave the diver less than happy and that it did not pass the CE test in that particular orientation.

It specifically says it doesn't meet the hydrostatic imbalance test in a 90 degree head down position and that it can cause the ADV to free flow if on. It's an odd position for a rebreather diver to be in, not being head down but being 90 degrees head down.

 

[kensuf]

Unless you're trying to get into lower orange grove...

 

[mikesz]

Mike,
Note you've bought your unit but I couldn't see one element covered in the feedback.

The interesting thing with rebreathers (like OC regs) is their WOB isn't subjective. It is a fixed constant for each specific rebreather specification. And variable dependent on design and DSV or BOV, BMCL or OTSCL or CMCL, Granular Sorb or EAC etc etc.

It will be a figure something like 2.1 J/L at 40m on Air at 75lpm for the rEvo IIRC.
No idea what the current variant of the Optima has been tested at?
Assuming both units are tested to the same standard, usually EN14143, you can then directly compare them. Exactly the same as OC regs tested to EN250; as were published in the old Diver magazine.
http://archive.divernet.com/Diving_Gear/group_tests/158687/15_regs_at_50_metres_the_tests.html
http://archive.divernet.com/Diving_Gear/group_tests/158688/15_regulators_on_test_the_regulators.html

Example of WOB testing for a rebreather with calibration methodology at https://www.opensafetyglobal.com/Safety_files/DV_OR_WOB_Respiratory_C1_101111.pdf
For those units the WOB 'is' the best on the market:
Single scrubber is 1.44J/L at 40m on Air at 75lpm
Dual scrubber is 1.38J/L at 40m on Air at 75lpm

WOB for a rebreather also has an OC component for its BOV
example https://www.opensafetyglobal.com/Safety_files/DV_DL_ALVBOV_Breathing_Params_A3_100318.pdf

Enjoy your unit.
If you need EACs, Apollo in Sydney import them in bulk direct from Micropore for the Open Safety military rebreathers they are the distributer for Micropore Brochure

Optima has WOB of 1.43 J/L at 40m on air. Optima CM is at 1.38 J/L

During my test dives, I did a few different tests to see how the unit would react. I went head down, head up and inverted (looking up at the surface from depth). To be honest, WOB felt just about the same in all positions, although my test dive was depth limited so probably not a good representation. I will get a much better feel for this once I do a few real dives.

Thanks for the heads up re EAC source. I’m not looking to use them due to the expense. I know their benefits and convenience, but equally, everyone I know locally diving Optimas uses sorb. The scrubber is easy to pack, lasts between 3-4hrs in local water conditions and is safe. That said, it’s good to know there is local supply if needed.

 

[Superlyte27]

Optima has WOB of 1.43 J/L at 40m on air. Optima CM is at 1.38 J/L

During my test dives, I did a few different tests to see how the unit would react. I went head down, head up and inverted (looking up at the surface from depth). To be honest, WOB felt just about the same in all positions, although my test dive was depth limited so probably not a good representation. I will get a much better feel for this once I do a few real dives.

Thanks for the heads up re EAC source. I’m not looking to use them due to the expense. I know their benefits and convenience, but equally, everyone I know locally diving Optimas uses sorb. The scrubber is easy to pack, lasts between 3-4hrs in local water conditions and is safe. That said, it’s good to know there is local supply if needed.

What’s your water temp?

 

[mikesz]

What’s your water temp?

Water temp on the day was 14C or 57F. Typical conditions around Melbourne are between 12-14C all year around and the guys I was talking to said it’s fairly consistent. Advice was, scrubber can go for 3-4hrs but you wouldn’t start a dive at near 3hrs. You’d finish all your dives, if you had to, at 3-4hrs but preferably at less than 3.

 

[Superlyte27]

Water temp on the day was 14C or 57F. Typical conditions around Melbourne are between 12-14C all year around and the guys I was talking to said it’s fairly consistent. Advice was, scrubber can go for 3-4hrs but you wouldn’t start a dive at near 3hrs. You’d finish all your dives, if you had to, at 3-4hrs but preferably at less than 3.

I agree

 

[mikesz]

I agree

Thanks for validating. The guys I’m working with are right up there in terms of experience and knowledge.

 

[Pod Diver Radio]

I currently teach on the CM O2ptima and should be teaching on the rEvo (it’s a long story-COVID BS). Needless to say I have a good amount of hours on both units.

I get asked quite a bit which unit I prefer. They both have trade offs. I guess the best answer is this. When I am going to dive for fun I have lately almost exclusively been grabbing the CM unit. That applies to deep wrecks in the 100M+ range and shallow photo focused dives and cave diving.

So I guess that being said between the CM O2ptima and the rEvo I would grab the CM unit. I truly believe it’s the most versatile unit on the market and weighs 14lbs ready to travel.

I just finished training on the CM with Jared and Lamar Hires. With your background, I would like to interview you for the Pod Diver Radio podcast. Let me know if you are interested.

You can listen to the post dive interviews here.
Optima CM Training Part 1
Optima CM Training Part 2
Optima CM development and applications