Posted by mike on January 15, 2001 at 21:03:18:
In Reply to: Why you need dive computers in California posted by Chris on January 15, 2001 at 19:27:30:
On my Indonesian trips, i can't plan my dives exactly because i never know where that ghost pipe-fish, orange frogfish, blue spotted sting-ray or crinoid squat-lobster will show up (In California, the dive plan comes first, followed by a lust for tasty bugs or good macro shots of deep critters).
As a consequence, i generally stay 10 to 20 feet above the DMs or guides and seldom go as deep as everyone else, (unless i see a gaggle of photographers fighting for position down there). I actually got into the yellow a couple of times on my last Sulawesi trip going after pygmy seahorses at 80 fsw (after piddling around for a half hour at 38 to 55 fsw chasing nudibranchs and crocodile fish) but knowing that my old beat up Oceanic Prodigy uses the Navy tables, i just spent the next 35 minutes at 32 to 15 fsw with the most time being spent at 18-25 fsw (and said, to hell with all that deep stuff, no photograph is worth getting bent), and then did a 5 min stop at 15 fsw followed by a 3 min stop at 10 feet (i do all that cautious stuff 'cuz at 4 to 5 dives per day for 10 to 14 days in a row, i don't wish to get an "unpredicted/undeserved/unexpected (choose one)" hit. I had an idea of how close i was to my NDLs but was still taken aback by the fact that after all that time in the shallows, my N-loading bar graph was still only two pixels from the yellow when i exited. And i was checking the darn thing the whole time just to get an idea of what the mysterious algorithms in their little black box were doing in relation to what my common sense (or lack thereof) and mechanical watch were telling me. I'm glad i didn't just pop to the surface after i felt like i had had enough deco time to satisfy my prudishness as i would have been pushing things a little bit closer.
I can see how one could get an intuitive feel for the algorithms, the same way that one tends to memorize the NAUI or PADI or whatever tables after enough years of diving (even with a computer) but without having the equations to work with, and a knowledge of one's own body composition by tissue type, I am still relying on my computer as a "security blanket" on which to double check my own semi-blind intuitive reckoning (i say semi blind, because there's still the tables and watch, in a pinch).
BTW, most of the other divers, guides included, went deeper than i did, and stayed there longer, but spent less time in the shallows, and exited sooner. Those guides gotta get bent every now and then, with their workload!