I guess I should clarify the rule regarding the relationship between flying and diving.

Flying before diving on the same day is generally accepted as okay. You should NEVER dive within the 24 hour window prior to flying. Some now use a 12 hour window, which of course is less conservative.

You guys probably remember this rule but here is its explanation anyway. When you dive the increased pressure of the water requires that you breath equivalently pressurized air to prevent your chest from collapsing. In this process your body begins to equalize within this increased pressure environment and thus absorb more nitrogen (air = 79%Nitrogen & 21% oxygen). Nitrogen is inert and for the most part merely sits in your system.

It takes time for this absorption process to occur. Where the problem arises is when pressure is released from your body too quickly and the "additional" nitrogen remains. If this occurs to quickly, then the analogy of opening a soda bottle and watching bubbles form will appropriately describe what is happening in your body.

So that is why we use dive tables for our own safety. However, dive tables do not account for the additional loss of pressure that occurs when you go aloft in an airplane. (Some new dive computers purport to do this.) As a result, scientists have formulated the aforementioned rule.

Here is a linkwith some valuable information.

I could get more technical with partial pressures but I think my basic explanation is functional.

[This message has been edited by CountinPlaces (edited 10-29-2002).]