halocline
Contributor
I always think accidentally staying over your NDLs is a bit like getting into a car accident.
If you keep d(r)iving long enough, it will happen sooner or later, no matter how careful you are.
That's only true to the extent that you can stay out of the way of bad drivers. I've been in two car accidents in my life; once getting rear-ended while waiting at a stoplight, once when someone ran a stop sign.
Whereas in recreational diving you can pretty much never blame getting into deco on someone else.
I'm not a big fan of the "all dives are deco dives" philosophy. I believe that there is a qualitative difference between situations in which you have immediate access to the surface in the case of emergency, and those in which you do not. The line is blurred a bit in the sense that you 'might' be fine surfacing with a small blown deco obligation, and you 'might' get bent rushing to the surface in an emergency, even if you are within NDL.
However, the idea that deco diving involves MUCH more than simply knowing how much time you need in a given situation is absolutely right. In that sense, taking a intro to deco course that stresses the type of gear, skills, and behavior that are part of being prepared for deco diving could be very helpful to strictly recreational divers, as it might influence their dive behavior during NDL diving.