The New Dive Rite Optima CM - My 30 Hour Review

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I tend to be really conservative on my bailout, probably more so than necessary. On a 200' dive with 2x AL80 (one of 50 and one of bottom gas/dil (18/45 or similar)) I find I am limited to 40 min TTS on the CCR (which becomes 60min TTS on bailing out). If I had a 100min TTS I would want 4x bottles but again, thats me and MY settings, YMMV.

When it comes to CCR diving, I am very much in the Richard Pyle school of "when I had 50 hours I knew everything, when I had 200 hours I realised I knew nothing". I am not sure where the cutoff of actually knowing stuff comes back, because I am not there yet.
You were nicer than me.
2x al80s and 1x al40 at 500ft is waaaayyyy light on BO. Like <50% of what's needed.
 
You were nicer than me.
2x al80s and 1x al40 at 500ft is waaaayyyy light on BO. Like <50% of what's needed.
No faster way to start a fight on a CCR thread than talking bailout. I recently watched a video of some guys doing insanely deep cave line pushing and their bailout seemed... less than optimal. But, I’m not diving to 220m plus so what do I know?
A 500’ dive is so far from anything I might ever do that I feel like I’m critiquing Neil Armstrong’s landing on the moon for being a “little bumpy”.
 
No faster way to start a fight on a CCR thread than talking bailout. I recently watched a video of some guys doing insanely deep cave line pushing and their bailout seemed... less than optimal. But, I’m not diving to 220m plus so what do I know?
A 500’ dive is so far from anything I might ever do that I feel like I’m critiquing Neil Armstrong’s landing on the moon for being a “little bumpy”.

Armstrong was a hack. Computers did it all for him. Like becoming a national hero for riding the bus.

That's a joke
 
does that include o2 cells tripping out? (In date). I have far fewer hrs on my O2ptima, but have had two dives where either a bad cell, or bad connection caused one cell to flake out within the first 10m of the dive. Of course there are four cells, and I probably didn’t need to turn the dive, but in one case it was a training dive, and didn’t want my instructor to count it against me if I ignored the issue.

*I still believe the O2ptima to be a highly reliable eCCR, just a little surprised by a claim of 1000hrs with no failures.

Any rebreather might lose a cell for a few minutes during a dive. It happens when a drop of water hits the cell. It usually corrects itself pretty quickly. I've never called a dive because an optima wasn't able to dive.
 
You were nicer than me.
2x al80s and 1x al40 at 500ft is waaaayyyy light on BO. Like <50% of what's needed.

Based on what? I'll have a conversation in private, because I'm not going to teach people how to do this stuff. But most of your assumptions are probably way off.
 
I tend to be really conservative on my bailout, probably more so than necessary. On a 200' dive with 2x AL80 (one of 50 and one of bottom gas/dil (18/45 or similar)) I find I am limited to 40 min TTS on the CCR (which becomes 60min TTS on bailing out). If I had a 100min TTS I would want 4x bottles but again, thats me and MY settings, YMMV.

When it comes to CCR diving, I am very much in the Richard Pyle school of "when I had 50 hours I knew everything, when I had 200 hours I realised I knew nothing". I am not sure where the cutoff of actually knowing stuff comes back, because I am not there yet.

You’re missing a pretty big qualifier in your math. What was your bottom time? My TTS was well under and hour when I started my ascent. I managed my PPO2 based on the ascent rate I wanted. On a 200’ dive you had what you had, but if your 200’ dive was less than a minute, how much bailout would you need. At any rate, I had WAY WAY more gas than I needed. But, I know a few things that you probably don’t.
 
does that include o2 cells tripping out? (In date). I have far fewer hrs on my O2ptima, but have had two dives where either a bad cell, or bad connection caused one cell to flake out within the first 10m of the dive. Of course there are four cells, and I probably didn’t need to turn the dive, but in one case it was a training dive, and didn’t want my instructor to count it against me if I ignored the issue.

*I still believe the O2ptima to be a highly reliable eCCR, just a little surprised by a claim of 1000hrs with no failures.

I wonder what your maintenance looks like. You shouldn’t be having cells drop out with proper maintenance and good cells. Granted, when I was using Maxtec cells, they were failing left and right. But I quit using those back in the rEvo days.
 
So, to answer my own questions about how much bailout you need for a 4 hour dive at 100’ in open water, let’s do a bit of math off the cuff.

I’m going to guess at some of the numbers, but they’ll be close. You can verify them if you want. But at 4 hours at 100’ puts your deco at just under 90 minutes. Your first stop is at 50’ I think. It might be 60. But I’m pretty sure it’s 50. I’m going by memory. Granted, this is a dive on air at 1.2ppO2.

So, 90 minutes, with less than 15 of it being between 50’ and 20’ I’ll do this gas on 32% Bailout. At 20’ I’ll switch to Oxygen. So, 15 minutes on 32%. That’s an AL40. And 75 minutes on Oxygen, that’s also an AL40 of O2.

So, a 4 hour dive with a 1.2 set point with just two AL40’s for bailout/deco, in open water.

Anyway, this is pretty close based on a 4 hour dive we used to do a lot.
 
I have both.
appreciate the response. I'll assume petrel as the controller, but ill stop asking for free game. Mainly looking for feedback on useability of the nerd controller before placing my order. Have an older nerd and love it, but havent had any experience using it as a controller.
 
appreciate the response. I'll assume petrel as the controller, but ill stop asking for free game. Mainly looking for feedback on useability of the nerd controller before placing my order. Have an older nerd and love it, but havent had any experience using it as a controller.

Just tell Lamar to set it up likes his is set up. And you only need AI on Oxygen, so wouldn't bother buying two transponders.
 

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