I was thinking about this train wreck of a thread over the weekend, specifically the points made about "convenience" and "data logging."
I recalled that when I was a newer diver I constantly, almost obsessively checked my SPG, due to the fear of "running out of air." At the time, I might even have taken interest in Kevrumbo's tongue-in-cheek suggestion of AI gauges on both my wrists plus a heads-up-display for good measure. So, as mentioned previously, perhaps there is some relationship between the definition of "CONVENIENCE" and a diver's experience level and hence comfort level. I'm not saying that anyone who deems AI "convenient" is therefore an inexperienced diver. Stuart and other experienced divers here apparently find it convenient even for technical diving. Anyway, as I gained experience I checked my SPG less often. It was probably not until I took the GUE Fundies course that the idea of checking the SPG "only to confirm what I already knew" clicked with me. That, coupled with being taught to check the SPG manually in just a few seconds, is probably why I don't presently see myself wanting AI. It might be fun to see my pressure displayed on my wrist, but I was taught to do it the way I was taught, and it works perfectly for me. I'm not changing how I dive now, as it's a system that's ingrained in me. I won't completely rule out AI in my future, but I am more than content with my present system and training in this regard.
Similarly, there might be some relationship between experience and the desire for "data logging." Again, I'm not saying that anyone who likes the data logging feature that AI provides is therefore an inexperienced diver. However, my impression is that, on average, more experienced divers log less. Experienced divers, especially tech divers, generally know their SAC like they know their height or weight. They might go through the calculation now and then to update/confirm it, but that's all. If and when the diver wants to do that, it seems to me it's easy enough to write a few numbers on a slate or just memorize them (specifically, starting and ending pressure and average depth) and calculate later. I don't see the point in knowing one's "instantaneous" SAC or RMV. Isn't it sufficient to simply know that it goes up a bit when you're stressed or working hard and goes down a bit when you're relaxed and just floating along? How much accuracy is useful? You calculate some average over a few dives under different conditions that you generally encounter and use that number in your future planning, until such time as you feel like updating/confirming it again. All you need is an average, from which you can then in your dive planning, if you wish, adjust up a little or down a little to account for different conditions. Extreme accuracy, such as knowing your SAC was exactly X when you were diving under conditions A, B, C and D, doesn't seem to me to be of as much practical use as a simple average, since conditions are rarely exactly the same on any two dives.
The day I miss the whaleshark because I spent an extra three seconds looking at my SPG when I could have been glancing at my wrist is the day I will switch to AI.
