Abbo

Three rebreather divers died this week. Don't become another one - of course for your sake but also for the sake of everyone who knows you. I can understand taking risks to do something or see something nobody has done before, but pushing scrubber duration serves absolutely no useful purpose: the stuff isn't even particularly expensive.

There was a case reported on Rebreather World where a diver died trying to give himself experience of a CO2 hit. Clearly it isn't always possible to recognise the effects and react in time. Even in laboratory conditions, scrubber life appears to be pretty unpredictable, even taking out the obvious variable of how well it was packed. Then there is the large variability of CO2 production in your body, with work rate, stress and mood. On OC we dived 'rule of thirds', so it is no surprise that scrubbers can at least last half as long again as the published number. The effects of hypercapnia seem to come on too fast, which is why BOVs are getting the attention they are: the reports on this site say that just closing the loop and pulling out a reg is really tough in a CO2 hit. CO2 is of the order 175x as narcotic as nitrogen, so you won't be thinking clearly. Even when one day we have reliable CO2 sensors, this seems one thing there's no sense screwing with. There have got to be better places to channel your thirst for adventure.