DiveRite Optima CM upgrades

[addohm]

I understood what you meant. You want to draw diluent off of two separate tanks while on the dive. While in "Theory" it sounds fine. In practice it is not needed, and creates failure points for no real value. If it is needed, then you are definitely doing something wrong.

MY last Choptima dive was for 159 minutes at 90 ffw. According to the Shearwater NERD2 download I used 352 psi out of a LP 85. That is a bit less than 23 FT3.

How much are you using?

I'll probably get shredded for this but I'll share. The dil was AL80 and the o2 is AL13. Keep in mind I am new to rebreather diving and maybe have 60+ hours on it. The time marked (1h52m) was when I completed _my_ deco and bailed out. I stay in the water until everyone is finished safely. The blue line is my o2.

 

[Capt Jim Wyatt]

I'll probably get shredded for this but I'll share.

No one is going to give you a hard time. I am reading 159 bar from an AL80, so about 2300 psi or 61 cubic feet. That is a lot of gas. The graph shows a definite sawtooth profile with depth changes from 20-50 meters. I am assuming meters, not feet since pressure is bar and nor psi.

 

[Tracy]

I'll probably get shredded for this but I'll share. The dil was AL80 and the o2 is AL13. Keep in mind I am new to rebreather diving and maybe have 60+ hours on it. The time marked (1h52m) was when I completed _my_ deco and bailed out. I stay in the water until everyone is finished safely. The blue line is my o2.

O2 usage looks pretty normal for a dive like that. Basically 200L in 2.5 hours. That doesn't seem abnormal to me for a sawtooth dive.
The dil usage seems high. Could you be overweighted? That would cause more suit and wing gas than needed. I don't think you are breathing it as that would cause your o2 usage to be much higher unless you are running a rich dil.

 

[AeroSpartacus]

Was there a reason for the bailout? It seems like you would want to stay on the loop even if you were just waiting for buddies to finish their deco. (unrelated to the dil usage)

 

[addohm]

Was there a reason for the bailout? It seems like you would want to stay on the loop even if you were just waiting for buddies to finish their deco. (unrelated to the dil usage)

No reason to keep using O2 and I don't struggle with buoyancy and trim at all on open circuit. I use that time to experiment with my trim and buoyancy struggles by going on and off the loop to see the effects.

 

[addohm]

No one is going to give you a hard time. I am reading 159 bar from an AL80, so about 2300 psi or 61 cubic feet. That is a lot of gas. The graph shows a definite sawtooth profile with depth changes from 20-50 meters. I am assuming meters, not feet since pressure is bar and nor psi.

Correct, I'm an all-metric American

 

[Tracy]

View attachment 875635

Another question. Are you running the same setpoint for all depths? What is it?
There seem to be a lot of o2 usage spikes that don't correlate to a depth change. Are you trying to run the unit manually?

 

[addohm]

Another question. Are you running the same setpoint for all depths? What is it?
There seem to be a lot of o2 usage spikes that don't correlate to a depth change. Are you trying to run the unit manually?

I run 1.1 after 25 meters until about 6 meters. The latter number being somewhat arbitrary. I do squirt in some extra o2 during deco but not often.

 

[kensuf]

Again, I was speaking to while diving, not in between dives.

I logged a hair over 7 hours on ccr over the weekend at 3 different dive sites. I used 400 psi of DIL out of an AL 80 for the entire weekend.

 

[Tracy]

I logged a hair over 7 hours on ccr over the weekend at 3 different dive sites. I used 400 psi of DIL out of an AL 80 for the entire weekend.

so that was you laying on the bottom of the pool at Blue Grotto?