(I hope this question hasn't come up recently!)
I am a private pilot who dives occasionally. I've seen guidelines such as this one http://faculty.washington.edu/ekay/altitude.html, but many guidelines seem overly conservative. Why isn't flying after diving treated like additional loss of depth? For example, flying 3,000' is about 3" of Mercury or about 0.1 atmosphere. Can't that be factored into one's interpretation of depth tables? But I haven't seen that done. Why not? What's different about the change in pressure due to flying and the change due to diving? Let me take an example from the guideline (above)--it says that one should wait 8 hours before flying to 4,000 feet. That's about 4" of Mercury. Isn't that like diving to about 4 or 5 feet and ascending? What am I missing?
I am a private pilot who dives occasionally. I've seen guidelines such as this one http://faculty.washington.edu/ekay/altitude.html, but many guidelines seem overly conservative. Why isn't flying after diving treated like additional loss of depth? For example, flying 3,000' is about 3" of Mercury or about 0.1 atmosphere. Can't that be factored into one's interpretation of depth tables? But I haven't seen that done. Why not? What's different about the change in pressure due to flying and the change due to diving? Let me take an example from the guideline (above)--it says that one should wait 8 hours before flying to 4,000 feet. That's about 4" of Mercury. Isn't that like diving to about 4 or 5 feet and ascending? What am I missing?