ajduplessis
Contributor
I took PADI tec 40 and 45, and one thing that bothered me was following the run time, starting from the initial ascent, through the bottom time and during decompression. Basically, the run time forces you to stick to a strict schedule, putting stress on you during critical tasks such as gas switches. It never made sense how you're supposed to carefully check your gas and depth and do a switch at the same time you're rushing to meet the schedule planned by your run time.
Then I moved to IANTD normoxic, and my instructors did away with run time. This allowed us, in team diving, to do our gas switches sequentially, so you can check your teammates switches, and start your deco time only when everyone has switched. So you don't have to stick to an absolute run time schedule planned at the start of the dive. It also makes more sense, for instance, if you had to spend a bit more time during a switch, to untangle a hose, or fix a buoyancy problem, which would throw off your run time for the rest of the dive.
So I say, why task load yourself and stress out trying to stick to a run time schedule -- to the point where rushing can compromise safety?
Firstly, gas switches are very basic tasks and if you find them stressfull you should not be doing these type of dives. Work on your skills like switches and the other poor examples you described. You should be able to do these without a mask and on the move. If you can't do this effectively how are you going to deal with it when things go south.
The idea of being "forced" to stick to the dive plan is whole idea!! If you cant dive a run to the number , you are in for a serious suprise. You are masking your shortfalls by relying on your computer.
Work on your skills and start to dive only with a BT and slate. This will force you plan better and work on the gaps....