Filmmaker Rob Stewart dies off Alligator Reef

[The Chairman]

it is probably more accurate to say that the RMS "estimates"

Guestimate might even be more accurate! That's not a dis, because it's so much more than most units offer.

 

[RichardC]

I saw Simon's presentation at EuroTek and, as he says above, the data he presented showed the RMS was;

fairly accurate with its predictions when operated in typical conditions of exercise and CO2 load.

For my part, I am happy to trust the RMS with regard to the cycling of the scrubbers and have found that to be very reliable for the two years I have had one (my earlier unit didn't). However, I wouldn't trust it very far into the second scrubber as there is no redundancy or margin for error in that situation.

With regard to the incident, if Rob's unit did have an RMS, it might (and I stress might) give some indication of scrubber history and whether the scrubbers had been replaced or cycled on the day. I don't know if it is possible for an expert to get more information from the Shearwater than a user would normally see, but I wouldn't be surprised and I think even the normal information might be of some use.

 

[CuzzA]

Doesn't the Hollis Prism or maybe it's the Explorer have a co2 sensor?

Edit: Looks like it's the SCR Explorer that also has the infrared sensor.

EXPLORER CO2 SENSOR

 

[muzikbiz22]

Doesn't the Hollis Prism or maybe it's the Explorer have a co2 sensor?

Edit: Looks like it's the SCR Explorer that also has the infrared sensor.

EXPLORER CO2 SENSOR

Hollis Explorer does deploy an Infrared CO2 sensor. Works well.

 

[Tassi Devil Diver]

I too have found the rEvo RMS extremely reliable for the four years I have been using my unit (though have had some issues with the temp probes which now seems to be resolved), and happy to use it down to the last minute of cycle time. I think it works so well because you have a second scrubber as back up and along with the work put in by rEvo developing the predictive algorithm. I look forward to seeing Simons Michel's presentation of his scrubber monitoring study at OzTec next month and I not that Paul from rEvo is presenting on CO2 scrubbers.

 

[TONY CHANEY]

The following is taken from:
scubish.com: Reference - Underwater Physiology - RESPIRATORY PROBLEMS IN DIVING
"While at depth, the greater partial pressure of oxygen in the breathing supply forces more oxygen into solution in the blood plasma. Some of this additional oxygen reaches the cells and helps to offset the hypoxia. In addition, the increased partial pressure of oxygen forcibly displaces some carbon monoxide from the hemoglobin. During ascent, however, as the partial pressure of oxygen diminishes, the full effect of carbon monoxide poisoning is felt."

This would suggest that contaminated gas is not necessarily a "silly theory". I have little knowledge of rebreathers but wonder if coming off the loop reduces the PP of O2.

Pure BS

 

[Patoux01]

Care to elaborate? I've also been taught CO kills you on ascent.

Only reason I'd expect no CO is because of the gases used, but since there's still a compressor involved...

 

[grf88]

Care to elaborate? I've also been taught CO kills you on ascent.

Only reason I'd expect no CO is because of the gases used, but since there's still a compressor involved...

Maybe Tony Chaney should contact DAN to have them correct their literature:
http://cloud2.snappages.com/ac566fc7767e6c89f0768bcb0ce70965749666d0/Safety in the air.pdf

Here is another Link to the DAN SA website where it was placed.
Divers Alert Network South Africa - Safety Is In The Air

 

[Ron Lee]

In these events it would be nice if the first post listed known factual information. In this one we know the deceased's name, the dive site, depth of dives (assuming they went to the bottom), name of Stewart's dive buddy, and possibly that they were on rebreathers. It may be factual that there was one male on the boat besides the boat captain. Multiple other issues are uncertain. Stewart's rebreather training may be known.

 

[RainPilot]

When this thread started he was missing and very little more was known. Everything else has come to light over the course of the search and subsequent events.