Posted by MHK on September 26, 2001 at 10:43:43:
In Reply to: Tables and adjustments posted by BadFish on September 26, 2001 at 10:34:20:
The tables are generally accepted up to 1,000 feet, after that the surface pressure is adjusted at 1,000 increments of MB's.. Altitude diving is a specialized form of diving and one that you shouldn't undertake until you get proper training. It's important to understand that at altitude you're under less atmospheric pressure and as such you are more vulnerable to DCI.
Furthermore, your buoyancy will be reduced in fresh water so you'll need to adjust your weighting.. If you want he specifics you'll note that a cubic foot of freshwater weighs ~ 62 pounds while a cubic foot of salt water weighs ~ 64 pounds per cubic foot. So you'll reduce your weighting accordingly..
Hope that helps..
Later