Cyrille,
The RB80 and it's clones allow for the use of an oxygen sensor. However, most people choose not to use them.
DIR does not preclude using an oxygen sensor, it just has a problem with relying on them. Sensors can be notoriously unreliable depending on their environment - temperature, humidity etc and so any unit that relies on a sensor (or group of sensors) to manage the level of oxygen in the loop fails some of the principals of DIR.
Shallow water blackout is due to not changing to an appropriate gas in shallow water. In fact, ideally, one should be on OC in shallow water.
The deco schedules using a RB80 and OC are identical, so no need to worry about that. I don't see a problem mixing RB and OC people so long as the OC people know about RB's.
Best,
John.
Quote: (Originally Posted by
Cyrille)
Hi Howard,
My instructor had a shallow water black-out when diving the RON last year... and all of this despite the fact that he is a very experienced GUE tech diver... He had to be ressucitated and taken to the hospital. Fortunately he survived the ordeal. I have difficulties to understand why having a ppO2 meter would not be DIR... If we follow this logic, then we should not use SPG's to read the pressure from our cylinders, should we? 
If someone would dive a pure oxygen rebreather at max. 6m, I would understand that a ppO2 meter is not needed. But for SCR/CCR diving this is another story, especially during the ascent when reaching shallow waters.
I believe that buddy pairs must be consistent when it comes to decompression diving:
- either 2 divers using rebreathers
- or 2 divers on OC
Else, not having the same decompression schema, one may not be able to help the other in case of emergency.
Kind regards.
Cyrille