How long of SI after the computer dies?

[gcbryan]

Charlie I am not disputing the idea that you move from the wheel to the square RDP between dives and back. What I am saying is that when you are diving a computer that even though it calculates your pressure with the same basic algorithms as do the the wheel and tables, the computer is taking samples more frequently and therefore adjusting the NDL time much more frequently than you would with either of the other manual methods.

Because of this if your computer fails and you do not have the exact times or depths, it would be very difficult for a person to safely revert back to the manual tables. Now if you did log your exact bottom time and depth and did have detailed information on times at various depths then you possibly could revert back. Regardless of the fact that you may be able to do this, Agency recommendations are thre that you do not do this as you cannot be sure that you did not exceed NDLs.

Add this to the fact that all computer brands do not give you the same amount of time underwater just as two wheels may not show the exact same data would lead to the argument that the diver with the computer should err on the side of caution and not dive again for 24 hours just in case they violated NDLs.

If a computer didn't keep you out of the NDL's you wouldn't use one and you wouldn't be worrying if it died or not, right? So, as was pointed out, if it keeps you out of the NDL's simply assume a worst case scenario (group Z) and sit out the appropriate time and do the repetitive dive accordingly (longer SI, shorter dive).

It's true that on an individual dive you can get more bottom time with a computer than with the tables if you are doing a multi-level dive because of the constant sampling of the computer vs the table but that is only a shortcoming of the table when used for multi-level dives. Both methods are safe however one is more accurate for that type of diving and therefore allows for longer bottom times.

It would be dangerous potentially if you tried to get the same type of bottom times on your repetative dives after your computer died but this is not what is happening. You are using the table (conservative) using the worst case group Z (conservative).