Shotmaster
Contributor
Open circuit problems make themselves known, rebreather problems are silent killers. Big difference. Like I said, if you want to play astronaut, be my guest, until the sensors become fool proof, I won't be diving one.
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
Depends I have had a regulator fail at 100ft, air stopped flowing. That tank was lost, I had another tank and was able to breath off of it, but due to a faulty second stage I could receive no air from that tank and my dive is significantly shorter. Say I had an complete failure in my O2 reg where no gas would flow from that. I can still breath off my dil and I have hoses on my bail out. I still have working scrubbers so though I will still have to abort a dive I still have the same amount of time to deal with getting out of an overhead environment, deco, and what ever else I need. Now back to the diligent diver when the 2nd stage failed it was very apparent, breath in and nothing comes out. An O2 failure requires the rebreather diver to watch his PPO2 to see there is a problem. Rebreathers do add complexity to a dive, but they do give more options as well. It is about mitigating what the risks are that pose the biggest problems. If I am only going 70 or 80 feet for an hour a rebreather may not be the best tool, I am adding complexity to a dive that does not require it. If I am doing a 200ft trimix dive to penetrate a large ship to get to a specific room something like a 2nd stage reg failure would be a much bigger problem open circuit than on a rebreather. In that example if the rebreather completely fails then I am still an open circuit diver. Still a problem on a rebreather will sneak up on you and catch you off guard if you are careless or not diligent.
There is nothing fool proof. I fly multi million dollar aircraft and things have happened that when I landed engineers said "aren't supposed to happen". Just like flying diving is dangerous and there is no way to change that. The rebreather diver who expects the computer and cells to keep him alive is a fool, but the diver thinks her is perfectly safe OC will meet the same fate. There is no life support on the planet that is fool proof its not possible to happen something will always happen. On top of that the more you push the limits of what has been done the more unexpected problems can occur. CCR is not the answer for everything often it add way more complexity to out weigh the benefits of it. How ever as you push deeper and go to more places its nice to have 6 hours to solve many problems outside of a complete rebreather failure. Then I am still where I am when I put a set of doubles on and dive open circuit. It is a tool in my tool box some times I use it other times I throw my tanks on and go OC. The best way to be safe is to be well trained, know the equipment you are using be it open circuit or ccr, plan your dive, and dive your plan.