Techdiving Classes ?? TDI ??

[wrybosome]

I assume because he read that David Shaw had about 300 dives and got to die of a ~900' dive

Interesting, I had no idea Shaw only had 300 dives. Kind of hard to believe someone would try a dive like 800' down a cave with 300 dives. Actually, any number of dives really. 800' is a damn long way down.

His last dive is discussed extensively in this video from the DAN 2008 tech conference as an example of how work of breathing at 900' can kill you. Excellent presentation if you haven't seen it.

 

[kanonfodr]

The class is good for those who want less nitrogen and accordingly less narcosis.

According to Gas Mixer for Android, a mix like 25/20 would give you a ppO2 of 1.4 @ 151 fsw, with an END of 96 fsw. Sounds like a pretty good mix for the AN/DP range if you ask me.

Peace,
Greg

 

[rjack321]

I'm confused.

So if you do Deco Procedures with NO nitrox training whatsoever what are you qualified to do? 150 foot dives on air with no deco gasses??

Wow seems like pretty sophisticated, no wonder they have to break it into 2 classes

 

[rongoodman]

If you decide to go the TDI route, you'll have to do the Deco Proc or the new Helitrox course. Unlike most of the people think, the Deco Proc does NOT require Advanced Nitrox as a pre-requisite. Even Nitrox is NOT required.

Regarding the Helitrox, it's basically the Deco Proc class with adding up to 20% Helium. This one requires Advanced Nitrox.

It's also worth noting that you can do the Deco Proc or the Helitrox in conjunction with the Advanced Nitrox.

What would be the reason for taking the new Helitrox course, as opposed to Normoxic Trimix?

 

[rjack321]

According to Gas Mixer for Android, a mix like 25/20 would give you a ppO2 of 1.4 @ 151 fsw, with an END of 96 fsw. Sounds like a pretty good mix for the AN/DP range if you ask me.

Peace,
Greg

Actually recent thinking is starting to consider the reduction of CNS narcosis via helium may exacerbate the CNS toxicity of O2. So on trimix with significant workload at ppO2 of 1.4 is "worse" than the same ppo2 on just nitrox/air. Google Liz Halbach's death for an example, or there's an IUCRR report, date = July 14,2007

 

[rjack321]

What would be the reason for taking the new Helitrox course, as opposed to Normoxic Trimix?

You get to skip over the deep-ish air stuff at 150-160ft which is otherwise what AN/DP basically is. Normoxic trimix is considerably deeper and the ~200ft dives in normoxic would have ~2x as much deco. All in all jumping straight to normoxic would be really aggressive for beginning deco divers.

 

[rongoodman]

I have a trip booked to Florida in the fall for Adv Nitrox/Deco Procs, so I'll contact Dayo Scuba to see if they're teaching the new upgrade. An upgraded version of old TDI Deco Procs text would be nice to see--they redid Adv Nitrox last year and it's not too bad.

 

[rjack321]

I have a trip booked to Florida in the fall for Adv Nitrox/Deco Procs, so I'll contact Dayo Scuba to see if they're teaching the new upgrade. An upgraded version of old TDI Deco Procs text would be nice to see--they redid Adv Nitrox last year and it's not too bad.

I think the upgrade was geared towards AN/DP in colder lower vis waters like the PNW and UK. Less so for FL waters. Ask Doopler in the TDI forum, he can give you more info.

 

[Scott L]

I have a trip booked to Florida in the fall for Adv Nitrox/Deco Procs, so I'll contact Dayo Scuba to see if they're teaching the new upgrade. An upgraded version of old TDI Deco Procs text would be nice to see--they redid Adv Nitrox last year and it's not too bad.

The new TDI Adv Nitrox manual is simply a more verbose version of the former. Improved somewhat but much the same. Dayo Scuba is also teaches through IANTD. I would seriously consider combining Advanced Recreational Trimix which could all be accomplished over 3-4 days in that most dives will concurrently fulfill the mandated number of dives for all 3 certifications. IANTD's Tech-lite manual is much superior to TDI's IMO offering a lot of useful information beyond formulas, etc.

 

[Red Sea Shadow]

What would be the reason for taking the new Helitrox course, as opposed to Normoxic Trimix?

You should have either the Helitrox or the Deco Proc before going for the Normoxic Trimix. It's one of the pre-requisites.

The Helitrox is equivalent to the Deco Proc (150 feet, one deco gas, etc...), except that it permits using up to 20% Helium.