that's actually my primary concern as well. I also find myself taking longer to scroll through the menus and change settings on my nerd than my handset which is another light concern. I think the primary benefits of it would be less danglies when going through the wiggly bits and if I'm using the chest mounted unit as a BOB to my back mounted optima I would be much harder to confuse the controllers along with the unit being easier to clip on and off. I have some feelers out, but I think I just need to try one before making my decision. Worst comes to worst, I could always send it back and have them swap it over.
The New Dive Rite Optima CM - My 30 Hour Review
- Thread starter Superlyte27
- Start date
Please register or login
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
- Ability to post and comment on topics and discussions.
- A Free photo gallery to share your dive photos with the world.
- You can make this box go away
OP
Use a Shearwater or idecopro
Funny how you expect us to accept the word of a diving instructor in critiquing a new rebreather and its efficacy of its operation, yet you do not accept when photographs are provided to demonstrate a particular dive setup. What exactly do you need to believe something happens in real life?? How many pics do you need to believe it does happen?? In the meantime we will all accept your account of how a rebreather performs despite there being no third party or independent testing to validate this rebreathers performance, even though its a life safety system. But hey, that's not important as long as you say its great.
OP
At this point of the debate and I stress the debate not an argument, its very important the particular unit is not dragged into this as I am not questioning it. Its the principle that you espouse of "the factory dive instructor says this unit is ok to dive as he has done big dives with it, therefore it must be ok" and all we are saying is that when it comes to life safety systems being sold to the public, potential customers would like to see the performance claims about this unit independently validated, it can be by EN 14143 or by any other standard as long as its performance is independently verified by a recognised testing body.
P.s they sold more Ford Edsels and that still bombed.
OP
Lol, I'm guessing here in America, where people matter, the list of currently used CCR's on the market without your precious eurotrash standard far outweighs those with the standard.
FYI, there's currently about a 5 month wait on Sidewinders, and we don't even know how long the wait is on the CM. These seem to be the two most popular rebreathers in cave country lately. People here obviously don't seem to care about a standard imposed by some other country. They like these units so much despite the lack of EN cert that they're willing to wait nearly half a year for their unit. Get it yet? Lol
With love... -peter
Brad_Horn
Contributor
- Messages
- 231
- Reaction score
- 68
Actually, interestingly DiveRite appear to have gone to the serious effort for them, of partially conducting 1 out of the 50 tests required for EN14143. Though the WOB test for CE is done in cooled water at 4’C and at 75lpm as opposed to the much easier 40lpm that DiveRite considered sufficient. 40lpm is what is used for scrubber duration testing which they also haven’t bothered verifying for their CM unit.
O2ptima CM Testing | Dive Rite
Leaving us all too hazard a guess at just how high its EN14143 required 75lpm WOB is for actual comparison with CE’d rebreathers.
However, to put things in perspective for what users should be able to expect from a rebreathers WOB:
Optima CM 1.38J/L on Air at 40m at 40lpm.
But the market leading for WOB performance, Apoc Type IV CCR is 1.44J/L on Air at 40m at 75lpm.
So nearly the same WOB in the Apoc as the Optima CM at near twice the workload or put another way the Optima CM WOB is likely twice what it could be with proper engineering design.
The French Triton uses similar smoke and mirror tactics to avoid direct comparison of its WOB but at least it offers a lower WOB than the Optima CM. M3S Triton CM mCCR claims 1.57J/L on 10/90 at 100m at 75lpm. https://www.ccrtriton.com/triton-ccr-rebreather
And yes that same low WOB as the Apoc offers is perfectly achievable with a CMR as OSELs Incursion offers 0.6J/L on Air at 40m at 40lpm RMV for military users https://www.facebook.com/pg/OpenSafetyEquipment/photos/?tab=album&album_id=623950087634495 at this time.
Contrary to the DiveRite throwaway comment on their blog post that their CM is only marginally higher WOB than a properly performing OC 2nd stage. An OC 2nd stage is tested at 50m on Air at 62.5lpm for EN250 and a good one has a WOB under 1J/L… at that deeper depth and higher workload… See the Apeks TX100 OC 2nd stage WOB comparison http://www.deeplife.co.uk/or_files/DV_DL_ALVBOV_Breathing_Params_A3_100318.pdf
For those who think the US doesn’t have domestic testing criteria for rebreathers see pg 27 http://www.deeplife.co.uk/or_files/DV_OR_WOB_Respiratory_C1_101111.pdf and the USN TM N01-94 Air standard which the Optima CM fails by quite some margin. For the importance of this see the NEDU report by D. E. Warkander, "COMPREHENSIVE PERFORMANCE LIMITS FOR DIVERS' UNDERWATER BREATHING GEAR: OF ADOPTING CONSEQUENCES DIVER-FOCUSED LIMITS, Navy experimental Diving Unit TA 05-12 , 15 January 2007” which recommends a lower WOB limit and also gives elastance limits for rebreathers. This was a ground breaking piece of work in relating Work of Breathing limits to measured diver physiometric response.
Lol, I'm guessing here in America, where people matter, the list of currently used CCR's on the market without your precious eurotrash standard far outweighs those with the standard.
FYI, there's currently about a 5 month wait on Sidewinders, and we don't even know how long the wait is on the CM. These seem to be the two most popular rebreathers in cave country lately. People here obviously don't seem to care about a standard imposed by some other country. They like these units so much despite the lack of EN cert that they're willing to wait nearly half a year for their unit. Get it yet? Lol
With love... -peter
fathom doesn’t have any certs either and I could have cared less when I bought two of them and ain’t dead yet
Lol, I'm guessing here in America, where people matter, the list of currently used CCR's on the market without your precious eurotrash standard far outweighs those with the standard.
FYI, there's currently about a 5 month wait on Sidewinders, and we don't even know how long the wait is on the CM. These seem to be the two most popular rebreathers in cave country lately. People here obviously don't seem to care about a standard imposed by some other country. They like these units so much despite the lack of EN cert that they're willing to wait nearly half a year for their unit. Get it yet? Lol
With love... -peter
As a dive instructor is it possible that you stick with just the facts and present cogent arguments in a respectful manner on a public forum? Remarks like 'eurotrash' are uncalled for, everyone in this discussion has been more than polite with you all along.
'People matter' is an asinine comment. Its precisely because 'people matter' that we are arguing for life safety systems WOB to be independently tested and validated against its manufacturers claims with a known international standard. This way potential customers do not have to just take some instructors subjective word for it. Especially if they are a factory instructor, no conflict of interest there at all.
The NEDU report by D. E. Warkander, "COMPREHENSIVE PERFORMANCE LIMITS FOR DIVERS' UNDERWATER BREATHING GEAR: OF ADOPTING CONSEQUENCES DIVER-FOCUSED LIMITS, Navy experimental Diving Unit TA 05-12 , 15 January 2007” is actually worth reading and as an American study it can hardly be 'trash' as well!
All of the units referred to in this thread appear, from user reviews and dives completed on them, to be outstanding units, regardless where they are made. But the important word is 'appear' as we simply do not know how their WOB actually performs in a uniform perspective. And this is kind of important if people are going to trust their life with it.
And again it does not matter if the Standard is American or European, as long as the standard its tested with, is deemed acceptable by a competent party i.e. NEDU, E.N etc.
Similar threads
