Technical Diving and TDI

helo.

i have some questions about TDI and technical diving that i would like answering please. (quite alot - sorry for this)

ok. when i did my TDI advanced nitrox course i only read a manual and did not watch a DVD. do tdi not use DVD's for teaching? ALso when i did my course i only used 2 tanks. i had normal equitment with an extra high oxygen tank attached to the D rings on my BCD. i did not use a twinset. is the use of a twinset not required for this course? also for the other TDI courses do you have to go in a speciffic order or can you jump from 1 course to another? (eg. deco proedures to trimix) If (when i am 18) i want to do my deco procedures would i have to do extra training in diving with a twinset. also - why on my adv nitx certificate and card does it say that i can dive to 40m of salt water and not just 40m?

thanks and sorr 4 all the questions
Craig

:huh:

Didn't you ask these questions of your instructor? If not, shouldn't you?

From my limited experience, TDI does not use DVDs. All the advanced nitrox course does is train you in the uses and dangers of higher-than-40% O₂.

Did you do JUST the Advanced Nitrox without doing deco procedures?

Most people do a combined Advanced Nitrox/Deco Procedures course. It's actually pretty difficult/impossible to tell where one course ends and the other starts. In practice it might as well be one course.

My understanding is the only reason there is a separate Advanced Nitrox course is to do with rebreather divers needing it as a prerequisite for training??
(Not much point being certified for 100% O2 if you are not allowed to switch to it!!)

I believe Advanced Nitrox can be taught using a single tank with an H or Y valve (but I would feel shortchanged by that)

The last dive on my Advanced Nitrox/Deco involved 4 tanks. Manifolded doubles and 2 deco tanks.

The sequence is
1)Advanced Nitrox/Deco. Max 150 feet
2)Trimix (Normoxic) Max 200 feet Min O2 18%
3)Advanced Trimix (Hypoxic) Max 330 feet

Personally I like the TDI program. Nice,logical progression.

Never watched a DVD. Never felt I needed to.

I will answer your questions in order... and then have a couple for you! OK?

We use DVDs for some SDI courses but not for TDI.

If your course was a stand-alone Advanced Nitrox, two cylinders is adequate for the course.

NO the course does not require twins. It is usual for this to be taught as part of a general Decompression Diver or Helitrox Decompression Diver Program in which case the normal kit configuration is twins or sidemount; but even then, I have taught it to a couple wearing large capacity single with a slingshot valve.

Yes, there is a specific order to courses. Open Circuit progression is usually (in North America), Intro-to-Tech, Helitrox Deco (45m), Trimix (60m), Advanced Trimix (100 m). The programs that can be sprinkled in there somewhere are overhead programs such as advanced wreck and cave.

When you do your deco course, I would suggest working with your instructor to familiarize yourself with a twinset or sidemount rig... perhaps an intro to tech class but not necessarily.

It says 40 metres salt water because of convention.

Now questions for you if you don't mind.

What was it that compelled you to take Advanced Nitrox as a stand-alone course?
What depth did you do your training dives at?
Did those dives not incur any decompression obligation?

Anyhow, dive safe, dive often and have fun! And never mind about asking questions. That's one of the main reasons for this place existing!

thankyou 4 your time and answers. ok answers... i am 16 so cant do deco procedures, dived between 40-45m in my course. not deco

craig chamberlain:

thankyou 4 your time and answers. ok answers... i am 16 so cant do deco procedures, dived between 40-45m in my course. not deco

Click to expand...

That sounds like it clears up the confusion -- your expectations were of things in the 'deco' class training.

Maybe you could sit down with your instructor and have a good chat on your path of progression until you can take the later classes. Doubles are expensive -- but there are plenty of other areas to train in.