Quote:
| Originally Posted by scapaman just a thought,
but i thought that if you were to go back down to 6 metres all you would be doing is add to the nitrogen in your body. once your up your up and the damage is done , and do the agences say never to go back down?
just a thought .  |
Most agencies set a time limit as nothing happens quickly. A minute or two.
What you have is a minimum pressure that is considered safe for a given amount of dissolved gas. Decompression tables and computers estimate the gas in your body (which is an agreed formula that virtually all systems use) and the apply their own magic to guess the minimum amount of pressure you can safely ascend to.
You could run the rule that you never let the absolute pressure drop below the tissue 'tension' (equivalent of partial pressure but for dissolved rather than free gases) but this would give hugely long deco periods. The black art is deciding how soon you can come up. At 6m you are not gaining significant nitrogen but the danger with going back down is that if you have generated bubbles and a bad bend you need much deeper than 6m to recompress them enough to get through the narrow blood vessels and back to the lungs to be filtered and if you were to lapse unconscious you drown quite efficiently.
If you overshoot get back down to your stop depth at once. <slap>
If you've been a while get out of the water and breath O2. Not that there is anything magic about O2 other than it contains 0% nitrogen so all the gas transfer is outward.