Mailing List Archive Mailing List Archive
At 01:14 PM 10/5/2000 +1100, Jens Schamberger wrote: Hello Jens, >I do not dive mixed gases yet, but I look into >it and try to get some information first. >Just recently I had a conversation with a TDI >instructor and he told me they would use Nitrox >as travel gas then switch to air for travel and use >Trimix on the bottom. >I just could not see the logic in that procedure. I don't see the logic either. Unless you're diving *very* deep, (and I'm talking way past 300 feet here) a travel mix is not necessary. A healthy person can easily maintain hemoglobin nearly saturated while breathing a mildly hypoxic mix even during moderate exertion. People do it all the time when they go mountain climbing or skiing. At 10,000 feet, for example, the PO2 is equivalent to breathing about 15% O2 mix at sea-level. Prolonged heavy exertion at this pressure will probably make you a little light-headed but the few seconds it takes to get yourself to a normoxic depth a few feet underwater where the mix is normoxic isn't going to do it. On a side note, breathing 100% O2 on the surface to hyperoxigenate your blood just before jumping is nearly ineffectual since a healthy person already keeps hemoglobin nearly 100% saturated under normoxic conditions. You'd get more out of *mild* (emphasis on the word mild) hyperventilation before jumping to give you a *slight* CO2 deficit when you hit the water. I'm talking about one or two deep breaths of air here... the goal is a slight reduction in CO2 in anticipation of the CO2 buildup during the coming exertion... not enough to affect the breathing reflex. -Mike Rodriguez <mikey@mi*.ne*> http://www.mikey.net/aue Pn(x) = (1/(2^n)n!)[d/dx]^n(x^2 - 1)^n -- Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.
Navigate by Author:
[Previous]
[Next]
[Author Search Index]
Navigate by Subject:
[Previous]
[Next]
[Subject Search Index]
[Send Reply] [Send Message with New Topic]
[Search Selection] [Mailing List Home] [Home]