Posted by Ken Kurtis on July 20, 2001 at 10:54:31:
I got a different impression on JJ's computer comments when he made them as part of a DIR demo he did at our store about a year ago.
I didn't come away with the feeling that he was saying "No computers" or "Computing tables in your head is better than doing them with a dive computer." (And JJ, if you're reading this, please feel free to directly comment and correct me if what follows is NOT representative of what you meant.)
My impression was that his underlying message (and I happen to agree with this wholeheartedly and have taught this for years) was "Don't blindly rely on the information a computer gives you." Just because it says you have two minuts left at a specific depth, doesn't mean that's the gospel truth. In the same vein, just because your computer says you can go to 110' for 13 minutes on your fourth dive of the day doesn't mean it's a good idea.
What I got from his comments was that you should start with a basic understanding of NDL's and how nitrogen works in your body. Once you have that basis, you can look at the numbers a computer (or a table) gives you as exactly what they are - results from a mathematical model that may or may not pertain to your particular body physiology.
Now . . . armed with this general knowledge, as well as (because you've been paying attention throughout the dive) a knowledge of how deep you've been and for how long, IF your computer fails, you've got a logical basis of facts to ascend your way out of trouble (or perhaps even continue the dive - though that wouldn't be my personal choice) which might incorporate deep stops, extended stay at a shallow depth, etc.
And even if you're diving with an air-integrated computer, you should have a pretty good idea of how much air you've got left (because you've been paying attention during the dive) and won't be dealing with "Will-I-run-out-of-air?" concerns while you make your way back to the surface.
Maybe I misunderstood, but I did not take from the comments an advocacy to the diving community as a whole (despite what they might do at WKPP) to abandon computers or SPGs. What I heard was an advocacy to understand what we're doing, understand the information our gauges give us, and basically . . . to dive smarter. Nothing wrong with that in my book.
It's a message many of us (instructors, DMs, store owners, etc.) endorse and have been preaching for years but which frequently, unfortunately, falls on deaf ears.
Ken Kurtis
NAUI INstr. #5936
Co-owner, Reef Seekers Dive Co.
Beverly Hills, Ca.