TDI Extended Range - last words of advice?

[Scared Silly]

If I recall correctly, 130' was never chosen as the max depth for recreational diving based on END considerations ...

I would say you are correct because IRCC the limits are based solely on the PPO2.

For instance, the 135' (40 meter) limit is comes from the fact that at this depth the PPO2 is ~1atm and for those who wonder about 180' (55 meter) limit I believe the similar holds true. Except that the PPO2 is 1.35 which is just under the std max recommended PPO2 of 1.4 (at least by some agencies, other prefer lower limits).

 

[ianr33]

Now for a little more science. CO2 is the thing that has the most immediate impact on the body's acid/base homeostasis (Ph). CO2 combines with the bodies water to form carbonic acid, and a free hydrogen ion. More CO2, the body becomes more acid.

Agree that more CO2 makes the body become more acidic but the bit in the middle of this quote is not quite correct.

Water will combine with carbon dioxide to form carbonic acid
(H2O +CO2 > H2CO3)
Carbonic acid is a weak acid and will partially dissociate to a bicarbonate ion (hydrogen carbonate) and a hydrogen ion
H2CO3 <---> H2CO3- + H+

i.e. you dont get carbonic acid AND a hydrogen ion.

Now back to the Deep Air trashfest.

 

[Anti-Hero]

Awesome! It went from a question, to a debate, to a chemistry lesson in 8 pages.

 

[ScubaAndDreams]

You are all wrong, Helium is so 2000's...everyone should dive Hydreliox! You are all gonna die!

 

[Bismark]

What happens when your grandma gets anxious, hyperventilates, and feels lightheaded at the hockey game? You make her breathe into a paper bag, and try to calm her down.

Cheers

JC

Finally, something we can all agree on!

 

[rjack321]

Finally, something we can all agree on!

Time to use your wing as a RB eh Bismark? :mooner:

 

[Kevrumbo]

Going off to do my combined TDI Adv Nitrox / Deco Procedures / Extended Range course in the Dominican Republic on Sunday.

Any useful last words of advice from the tec veterans on the board?

Have fun! Give a day-to-day report on the class if you can. . .

 

[RiverRat]

Have fun Rhone Man! While you're out doing some real dives, I'm sure some of these other guys will go back to their little sandbox

 

[Web Monkey]

Going off to do my combined TDI Adv Nitrox / Deco Procedures / Extended Range course in the Dominican Republic on Sunday.

Any useful last words of advice from the tec veterans on the board?

• Stick close to your buddy
• Examine the dive plans closely and make sure you and your buddy have appropriate amounts of gas.
• Bring a good U/W watch.
• Depth and elapsed time are really important.
• Stay hydrated and get enough sleep. You'll need it.

Terry

 

[Chatterton]

What if I had a leftover H ion from my last dive?



Cheers

JC

Agree that more CO2 makes the body become more acidic but the bit in the middle of this quote is not quite correct.

Water will combine with carbon dioxide to form carbonic acid
(H2O +CO2 > H2CO3)
Carbonic acid is a weak acid and will partially dissociate to a bicarbonate ion (hydrogen carbonate) and a hydrogen ion
H2CO3 <---> H2CO3- + H+

i.e. you dont get carbonic acid AND a hydrogen ion.

Now back to the Deep Air trashfest.