We were doing safety stops in the 1970s; don't recall anyone rocketing to the surface; and while computers are, admittedly, a convenience, there is too much dependence placed upon them.
Dove a decade or more, simply, with a regulator, SPG, and a depth gauge, sans octopus; a ridiculous number of dives, before I purchased my first computer or safe second. Still keep tables in a bag.
Kept the Jetfins; passed the split-fin display . . .
would it be fair to say that with your initial training that the computer is non essential. and if so since the computer has arrived on the scene do you think that has caused agencies to stop training the aspects that for you made the computer a non essential. now making it an essential piece of equipment in relation to current diving curriculum. The reason I ask is to use a similar topic of cars spare tires and jacks. How to use a car jack used to be taught,,, now you are taught to use the cell phone and if that is no good you get the tank of fix a flat fill the tire and then continue driving to your destination or use the 50mph tire and use it untill you buy new tires. How to use the jack no longer gets taught. I see your point to a point. We also did not have emergency flashers. now we have them and you can count each day on your hand the drivers that act as if they were installed for telling other drivers to get out of the way because they are late for work school or an apt. Im not sure that todays divers without a computer have any tools to use.