Tech through PADI or TDI?

[rabe]

I'm following this because I am in the same situation: I'm ready to go tech and I'm pondering between PADI Tech 40 or TDI Advanced Nitrox Diver (which is the TDI version of PADI Tec 40, if I've understood correctly).
Now, we have really good school down here, so the choice is very hard.

Any comments or tips is more than welcome!

 

[sigxbill]

we have really good school down here

Are you saying that there are both schools, and both are really good? Or just one? I'm curious how you determined the school is really good? And if you know this to be true, then why is the choice hard? I find it interesting discovering how divers make decisions about advanced training ...

cheers

 

[rabe]

Are you saying that there are both schools, and both are really good? Or just one? I'm curious how you determined the school is really good? And if you know this to be true, then why is the choice hard? I find it interesting discovering how divers make decisions about advanced training ...

cheers

because I personally know the instructors of both schools and they are really good

 

[DevonDiver]

because I personally know the instructors of both schools and they are really good

Purely out of interest and curiosity ... on what criteria would you rate them?

 

[stuartv]

I'm following this because I am in the same situation: I'm ready to go tech and I'm pondering between PADI Tech 40 or TDI Advanced Nitrox Diver (which is the TDI version of PADI Tec 40, if I've understood correctly).
Now, we have really good school down here, so the choice is very hard.

Any comments or tips is more than welcome!

Not quite correct. TDI Advanced Nitrox is normally taught combined with Decompression Procedures, as one class. When taken as one combined class, the result is the equivalent of PADI Tec 45, not 40.

 

[northernone]

Not quite correct. TDI Advanced Nitrox is normally taught combined with Decompression Procedures, as one class. When taken as one combined class, the result is the equivalent of PADI Tec 45, not 40.

That's good to note. I don't think there's a padi direct equivalent to tdi advanced nitrox cert alone. I took my advanced nitrox course as a stand alone without decompression procedures as I needed it for some O2 fills. I also know be people who did decompression procedures who didn't want to do advanced nitrox as they didn't have an O2 source locally. For those situations I'd recommend TDI.

For a more generic dive situation I'd flip a coin. The agency debates have endless opinions and advantages either way. If both instructors are good pick whichever you like. Which shop would you like to spent the most time in during training? Does one smell better, have nicer parking or offer free lollipops? I'd recommend talking with the perspective instructors and having them explain from what they know if you, how their program would be a good fit for your goals. It's interesting to see how individual personality and mindset can change an agency debate to something more useful.

Enjoy,
Cameron

 

[boulderjohn]

With PADI, the ability to use greater concentrations of nitrox is built into Tec 40 and 45. A tec 40 student can use up to 50%. A Tec 45 graduate can use pure oxygen. The thinking is that there is not much use for those gases without decompression diving.

 

[DevonDiver]

There is a certain logic about PADI's TecRec/Tech Deep sequencing. It matches gasses with the decompression demands/needs of the dives at that level.

Tec40 = >50%, single deco gas. That's a prudent gas for a qualification that only permits max 10 min non-accelerated deco. 50% provides a good level of conservatism for the fledgling tech diver.. somewhat offsetting the risk of being 10 mins beyond NDL. It also provides a logical safeguard against OXTOX risk... where a moment of inconsistent buoyancy won't subject you to excessive ppO2.

Tec45 = >100%, single deco gas. This level is now full, accelerated deco. The diver has done 2 tech courses, so skills, procedures and tolerances should be reliable. This gives the tech diver the option of whatever O2% deco most suits their preferences / philosophy / model for ascent. However, at the same time, dives to max 45m are unlikely to have so much deco obligation as to necessitate a second deco gas. Having multiple deco gasses exponentially increases the risk of diver error leading to an OXTOX emergency, so this rise in complexity is logically withheld to the next phase of training - Tec50.

Tec50 = >100%, multiple deco gasses. With 3 courses complete, the tech diver should have a high standard of procedures and competencies. The use of multiple deco gasses (i.e. 50% + 100%) is logical for extended range depths with more lengthy deco obligations.

As you can see, the syllabus progression matches the gas options to the likely necessities of the dives at that level, whilst also withholding what's unnecessary and would pose extraneous risk to the diver.

 

[stuartv]

Tec45 = >100%, single deco gas. This level is now full, accelerated deco. The diver has done 2 tech courses, so skills, procedures and tolerances should be reliable. This gives the tech diver the option of whatever O2% deco most suits their preferences / philosophy / model for ascent. However, at the same time, dives to max 45m are unlikely to have so much deco obligation as to necessitate a second deco gas. Having multiple deco gasses exponentially increases the risk of diver error leading to an OXTOX emergency, so this rise in complexity is logically withheld to the next phase of training - Tec50.

You don't count on the the diver having reliable skills, procedures, and tolerances after the first tech course?

If you DO count on those things (which seem reasonable, to me, for a competent instructor to be able to produce in one course - from what I've read, I would bet that your tech students have pretty solid skills, procedures, and tolerances after passing their first course with you), then do you really think the safety of the new tech diver really requires an intermediate step of 40m limit, and 50% O2 limit?

With OW divers, you teach them what they need to know to be able to dive to 130'/40m. But, you also tell them not to go straight to that. Instead they should start off with easy, shallow dives and gradually build experience and work up to diving to 130'. Why is it any less safe to teach a new tech diver to be able to use 100% O2 and dive to 150'/45m, but then tell them to start off with a leaner mix for deco, do shallower dives, and build some experience as they gradually work up to diving to 150' and using 100% O2?

 

[stuartv]

With PADI, the ability to use greater concentrations of nitrox is built into Tec 40 and 45. A tec 40 student can use up to 50%. A Tec 45 graduate can use pure oxygen. The thinking is that there is not much use for those gases without decompression diving.

From my pretty inexperienced point of view, that rings very true. There does not seem to be much use for diving with 100% O2 without also doing decompression diving.

I think that is why TDI Advanced Nitrox is almost always taught as one class combined with Decompression Procedures.

But, it's nice that TDI has the flexibility to offer Adv Nitrox as a standalone class for the people who need it and are not interested in decompression diving. I know of at least one active SB member that has somewhat unique needs and has benefited from taking TDI Adv Nitrox as a standalone course, without having to deal with the expense (e.g. diving with doubles) and hassle involved in also doing Deco Procedures.