Matsya:
Actually Mike aren't you and Rawls saying the same thing? He "decided" to ignore the computer based on experience and reasoning and that is what you are recommending one should do rather than blindly follow the computer or allow it to make decisions for you !!
I don't think so. I don't use a computer because I plan my decompression, including contingincies, by other means. It sounds to me like Rawls stoped following his computer because he didn't like what it said and switched to following some one elses computer. It's too early in the morning for me to know just how to put it into words but I don't think it's the same thing. If nothing else, when in doubt, follow your training. What are divers taught to do given the outputs of multiple computers? I think they're taught to follow the more conservative computer, aren't they?
The computer does not go into lock mode to prevent you from doing subsequent dives. It goes into lock mode because its algorithms for calculating NDLs, deco stops etc.are no longer valid since the calculations have now to be made based on the recorded data of previous dive(s) that violated the algortihms. If the intention was to prevent further dives altogether and make that decision for you, the computer would not have the functionality of gauge mode.
Really? This might be a little hard to discuss without using a specific computer and a specific dive profile but exactly how does a recreational diver doing no-stop dives keep diving after their computer locks up? Aren't they likely to be off their no-stop tables? I'm not sure what you get when you overlay a haldanian model with elements of a bubble model as I think some computers do now but, in the case of a haldanian type model, I don't see why the computer can't keep crunching the numbers. The computers that I've used do just that. I think the lockup modes are absolutely intended to keep the diver out of the water if they were relying on the computer for decompression information. Look in the book for your computer. What does it suggest you do in the case of an error that locks up the computer?
Back on the subject of doing a disservice to new divers, I'm not telling any one that they shouldn't plan their decompression but there are ways other than computers. I also wouldn't tell some one who is using a computer not to follow it. If a computer is your choice for decompression information then you should probably follow it.
What else would I say to a new diver? A dive team made up of divers who are diving different models is as wacky a thing as I can imagine unless the planned dive is within the limits of
all the computers. The whole team needs to plan on the same ascent schedule because they should ascend together. This seems like a complete no-brainer. If one diver has a problem during ascent that requires that they go to some contingincy plan then the rest of the team is with him. In other words lacking any decompression information besides the outputs of the computers, I think that Rawls should have followed his compter and his buddies should have stayed with him...NOT the other way around. Maybe his computer was off in left field but he didn't think so when he baught it or when he started the dive. He also didn't state the exact nature of the error but I would think it needs to be fairly significant to shut the computer down for 36 hours. No? If his computer is just that incredibly conservative, refer to point one...a dive team made up of divers using different models makes no sense at all unless they plan on diving a profile that they know to be within the limits of ALL the computers! This dive clearly didn't fit that description.
This was a training dive? I'd love to hear the instructors story too.