The New Dive Rite Optima CM - My 30 Hour Review

[cathal]

fathom doesn’t have any certs either and I could have cared less when I bought two of them and ain’t dead yet

Yep, from what I hear its a fantastic unit. Best of luck with them and enjoy!

 

[MichaelMc]

Superlyte27, thanks for the CM review and discussion! Being so light makes it appealing for simple dives. Setting aside that it may be fully functional well beyond that. Thanks!

 

[rjack321]

fathom doesn’t have any certs either and I could have cared less when I bought two of them and ain’t dead yet

Other than the fact that Charlie runs the fathom scrubber backwards (and makes the canister itself intolerant of flooding, and untested in that direction) to make the head easy to manufacture what could go wrong?

 

[silent running]

Other than the fact that Charlie runs the fathom scrubber backwards (and makes the canister itself intolerant of flooding, and untested in that direction) to make the head easy to manufacture what could go wrong?

The Fathom scrubber does not run “backwards”. It runs the right direction, inside to out, if you care about scrubber thermal efficiency and condensation being diverted away from the sensors by allowing it to form on the scrubber bucket wall, before the gas hits the sensors. This has been known as the best arrangement for a long time and is the same basic gas path as the Prisms. Flood tolerance is not as important as the proper functioning of O2 sensors and maximum thermal efficiency for CO2 removal, IMHO.

Oh, and BTW, the Prism radial in to out scrubber was tested extensively by the NEDU. So the scrubber efficiency characteristics of the Fathom are by extension, tested and validated. The scrubber bucket is made out of some new epoxy which has very good insulating characteristics, it might even be more efficient than the Prism’s epoxy bucket...

 

[rjack321]

The Fathom scrubber does not run “backwards”. It runs the right direction, inside to out, if you care about scrubber thermal efficiency and condensation being diverted away from the sensors by allowing it to form on the scrubber bucket wall, before the gas hits the sensors. This has been known as the best arrangement for a long time and is the same basic gas path as the Prisms. Flood tolerance is not as important as the proper functioning of O2 sensors and maximum thermal efficiency for CO2 removal, IMHO.

Oh, and BTW, the Prism radial in to out scrubber was tested extensively by the NEDU. So the scrubber efficiency characteristics of the Fathom are by extension, tested and validated. The scrubber bucket is made out of some new epoxy which has very good insulating characteristics, it might even be more efficient than the Prism’s epoxy bucket...

Shrugs, I don't really care.
It sucks for flood tolerance. No other radial runs that direction, the Meg and Golem canisters used in fathoms were not designed or tested to breathe that direction. It does make the head much easier to machine than any other comparable unit (iQsub or Meg). The prism is a terrible unit by modern standards so saying "its like that" is not exactly a compliment. With less than 40 units made, time will tell if Charlie's implementation ends up net positive.

 

[silent running]

Shrugs, I don't really care.
It sucks for flood tolerance. No other radial runs that direction, the Meg and Golem canisters used in fathoms were not designed or tested to breathe that direction. It does make the head much easier to machine than any other comparable unit (iQsub or Meg). The prism is a terrible unit by modern standards so saying "its like that" is not exactly a compliment. With less than 40 units made, time will tell if Charlie's implementation ends up net positive.

Don’t care about sensor errors due to condensation? Don’t care about scrubber efficiency? How many scrubber floods have you had?

The Prism 1 has very good WOB and scrubber efficiency and the only architecture which allows PO2 monitoring without any electronics or battery. I don’t really care about “modern”. In 1000+ hours, I’ve never flooded a scrubber, never had a CO2 hit, even at the end of a scrubber during max exertion, and never had to abort a dive except for operator error in the form of a pinched scrubber o ring. Which I noticed during the beginning dive bubble check, got out of the water, fixed it and was back in the water in under 20 minutes.

I once got a rip in my exhale CL, had about a pint of water in it. Didn’t notice it until after a 3hr dive and none of it made it into the scrubber, because the CLs functioned correctly in their second purpose, to trap water and keep it from entering the scrubber...

 

[Superlyte27]

You guys go argue about your inferior rebreathers on your own page

 

[rddvet]

Other than the fact that Charlie runs the fathom scrubber backwards (and makes the canister itself intolerant of flooding, and untested in that direction) to make the head easy to manufacture what could go wrong?

It's the only unit I've used, so what do you mean backwards? I'm not sure how the gas flows differently. Are you talking about the inhalation coming from the inside of the scrubber and not the exhale going through the middle and out? I don't see why that would affect flood tolerance, but I'm happy to learn. One of the reasons I chose the fathom was that it's considered to have excellent flood tolerance.

Edit.. I may have written the air flow backwards, but I'm not going back to fix it, you get the point.

 

[Aquanomad]

Would love to see some more pics of this breather. Likin what Im hearin.

 

[Superlyte27]

Would love to see some more pics of this breather. Likin what Im hearin.

I'll get you some soon.