We're never going to solve this issue since it comes down to, heaven forbid, what is important to you. Not whether your brain will rot or you'll live to tell about it.
This is a tool for specific uses and applications, with specific requirements for proper use - not a panacea. Then again, what is? I won't comment.
For a single rec. dive, a lot of this deco profile tracking is immaterial, whether mental or computer, since your gas supply is most likely to dictate your course of action. However, sound diving practice does apply. (slow ascents, stops, limiting bouncing and strenous activity)
This deco tracking becomes critical when doing deco and/or repetitive dives. A computer can get you out of the water faster since it tracks your actual dive profile more precisely than mental tracking, therefore you will not need to do additional deco time in order to compensate for a greater degree of imprecision. Of course how safe one chooses to be is up to the individual. Yes, I know deco is an imprecise science, or is it an art? But we all use some type of guidelines which we follow. I hope.
The importance of this is up to each individual to determine. The primary benefit of deco meters is to maximize bottom time and minimize deco stops times, since your actual dive profile is tracked and applied to your deco model with greater precision than mental tracking. This is only part of the "dive plan" and not fool proof. Then again, what is?
Leadweight, thanks for the suggetion to look in the Dr. Deco column. I have found this column along with the other medical column incredibly informative and can highly recommend that everyone takes a look at it, even if they may find much more than they ever wanted to know. You will find many good, easy to apply tips.
Sometimes in discussing a certain issue it may appear that a greater understanding is not known if various specific subjects are not addressed.
Since I think we are now spinning in circles, I like to discuss an issue I have not seen discussed before: forward projections.
In the previously postulated scenario where you have to go back down to help a buddy. Lets say you presently have a deco obligation, and wish to have an idea of how deep and how long you can still go and still complete your new and greater deco obligation based on gas supply, or for that matter by how much you will have to violate deco. When viewed in light of the fact that this estimate is likely to need on the fly real time adjustments (possible stress will increase your gas consumption as an example) and a computer will display where you currently stand at any one point, how important is it to know this information before hand and how is it useful?
To try and answer part of my own question. This forward projection knowledge will be helpful in assisting you to determine how much of an additional risk and deco liability you are taking. Beyond this, for someone who is willing to take an additional risk and is able to monitor current gas and deco demands and make a decision to abort when he's reached his limit, how useful is it to know that you may have 5 minutes at 20 ft greater depth before your risks become too great? I assume that if this knowledge is available before hand one may be able to approach the task at hand more calmly. Then again it could prove a distraction. Frequent monitoring of deco meter could have the same consequences.
The same could be said for rec level diving not so much with respect to a major deco obligation but gas supply.
I wonder if some of you can further expound on this subject.
Are there some computers suitable for deco where if you violate a deco obligation (say you only did 8 min. at 50 ft instead of 12 min) allow you to bypass this obligation and recompute the next level obligation (say you now need to do 15 min at 40 ft instead of 8) or do they all remain stuck "brain dead" (I know some of you will like that) on the lower level violation all the way to the surface in the event you do not go back and complete that specific deco obligation?
