I'm glad to see this conversation because of questions I've long had myself, but was hesitant to ask. Please correct me if I'm way of base here, but it seems that the effect of atmospheric pressure drop on the body is not linear, but rather it seems it is exponential. The above example of 1000ASL being equivalent to 1.2FSWA would seem to be insignificant, however using the same rational we could say that a dive from 33' to surface would be equal to surface to the edge of space. The rise from 33' to the surface has a fairly negligible effect on the body but the rise to the top of the atmosphere would be drastically worse for your health. (according to Dr. McCoy (Bones) your blood will boil in 13 seconds
) Since we also perform the majority of decompression time at a relatively shallow depth of 15' even after exposure to vastly greater pressures at depth, it would seem so. However this conclusion is not based on any significant study of empirical data so I may be completely wrong.
The reason I'm so interested in this is related to my other hobby, experimental aircraft. I finished building my own plane about 10 years ago, when I was just an occasional vacation diver using rental gear. At the time I was building I had this fantasy of flying it to exotic locations and diving before flying elsewhere. In the last year I started to pursue diving in earnest and have bought all of my own cold water gear, which is so heavy I've realized the impossibility of hauling 2 sets of gear with at least a spare set of tanks in a light aircraft... fantasy indeed! However I can't stop thinking about flying it down to more tropical locales where tank & weight rentals abound and required gear weight is minimized. Island hopping in my own plane seems like a fantastic way to get to some fantastic dive spots. If only it weren't for that pesky no-fly time. As I can choose to fly at low altitudes as well as set my own departure time, this can be managed, however should any sort of DCS be encountered during flight it would be rather inconvenient to say the least.
Since divers should share many personality traits with pilots, I'd be shocked if there weren't at least a few pilot/plane owners on this forum and a subject such as this should surely catch their attention. I'm really interested in what those with experience in this would have to say?