TDI Advanced Nitrox/Helitrox - what to expect?

[helios]

Hi everyone,

After a 4-month struggle, I've signed up for the AN/Helitrox course and I'm very excited.

I'm wondering if someone could provide some insight into what I should expect from the course and what I should put in to it, so as to get a good experience.

A little background about myself, I'm a PADI Divemaster and just shy of 200 dives. I do my primary diving in Denmark year 'round in a dry suit, and I'm not afraid to carry heavy things or work on underwater skills.

I'm very comfortable in a wing with singles, not having used doubles before and I feel like I have good trim and buoyancy in the water.

Thanks for any input

 

[VaeVix]

My last course was an AN/DP so I can relate a bit (DP because using helium before 60m is quite uncommon in Europe except for cave diving/DIR). YMMV, but be ready to re-learn the whole trim/balance, in my case not because of the double but because of the deco tank. I needed quite a few try to find a confortable way to clip it on the D-rings. If you're a DM with 200 dives the rest of the course should be pretty uneventful as I guess you can swim for 15m without a mask or regulator etc. The theory is also quite simple (though I have a STEM masters, but as a divemaster you should have covered most, especially if you're curious about diving). Of course the first time you hear your computer telling you "now you're into deco" is a pretty important moment in a diver's life (in my case my last AN/DP dive was 50 mins of NX 50 deco so it was a big gap from my PADI days).

 

[stuartv]

You don't mention it, but I assume you're doing Deco Procedures as well.

I just finished AN/DP at the end of April. My tech instructor is about to complete his Trimix Instructor cert, whereupon he will give me one more classroom session and then issue me a Helitrox cert.

According to my reading of the TDI standards, the ONLY difference between Helitrox and Deco Procedures is two chapters of the book - the Physiology section and the Planning section.

So, from my perspective, the answer to your question is:

- talk to your instructor as soon as you can to find out what your instructor wants you to have regarding gear.
- get the doubles and regulators that you need.
- put some time into diving with the doubles setup, in a somewhat controlled environment. Starting in a pool would be good.
- sort out your weighting requirements and trim. Being a DM, I expect you are perfectly capable of working out your required weighting and trim on your own.

Looking back, I feel like doing that would have been the biggest help to me when I started AN/DP. Instead, the first time I ever dived with doubles was the first pool session of my class. So, I ended up using multiple class sessions to get my weighting and trim really dialed in. Some of the early sessions in the water, where my weighting and trim were less-than-perfect had the effect of distracting me somewhat from the skills that were being taught. It all worked out fine and I was actually the first of the 3 students in my class to finish and actually get my cert. But, I do think if I had prepared myself more before the class started, I might have finished the class with even better skills than I did.

Adding an AL40 deco cylinder to my setup didn't really cause me any issues. Without training, I would not personally recommend that you add that to your mix. I'd say if you just get yourself sorted with the doubles, then when class starts and you do add a deco cylinder, you'll be totally fine.

 

[DevonDiver]

I feel like I have good trim and buoyancy in the water.

Weak fundamentals is what causes most frustrations during initial technical training. Many experienced recreational divers tend to over-estimate their competency at fundamentals, when embarking on technical training.

Only a few tech agencies have a baseline assessment of readiness for technical diving. Given the trend for technical diving training becoming more mainstream and accessible, more agencies should institute some form of pre-tech training and/or assessment. But.... profits...

The best in-water preparation you can do is to focus on those fundamental skills: weighting, buoyancy, trim, propulsion, planning and situational awareness. Those fundamentals need to be unshakable - i.e. they do not degrade when further task loading or stress is placed upon the diver.

I've attached a PDF that I use for assessment on my tech courses. It's not pass/fail... as it isn't a formal performance requirement for the certifications I issue... but it gives prospective students an indication of the standards I would hope they can achieve. It also gives them a criteria against which to practice in advance.

 

[stuartv]

It also gives them a criteria against which to practice in advance.

If they can do all that in advance, why take your class? Ha ha!

For your requirements on maintaining a hover +-60cm, it seems like you would specify a depth, too. Hovering at 30m is a lot easier than hovering at 2m.

 

[DevonDiver]

If they can do all that in advance, why take your class? Ha ha!

For your requirements on maintaining a hover +-60cm, it seems like you would specify a depth, too. Hovering at 30m is a lot easier than hovering at 2m.

Oops....I have a recreational level assessment also. That's what I meant to post - as it's more relevant to the OP. It's attached on this post...

My assessment dives are at 3-4m depth primarily, then drop down the adjacent wall for the ascent-based skills.

 

[stuartv]

Oops....I have a recreational level assessment also. That's what I meant to post - as it's more relevant to the OP. It's attached on this post...

My assessment dives are at 3-4m depth primarily, then drop down the adjacent wall for the ascent-based skills.

Or not....

 

[DevonDiver]

Slow upload... should show on the post now?

 

[stuartv]

Slow upload... should show on the post now?

Yup!

 

[AJ]

I did GUE Fundies and aim to go further. The thing that struck me most during the course was my relatively bad positioning in the water. Within recreational standards it was quite reasonable, but not by GUE standards. Also trim was not near what it should have been.

SInce then I have been practising (over 100 dives and almost that many hours) on fin kicks and hover within limits while performing drills. Now I have come to a point that I am close to Andy's technical requirements in all conditions. Precision diving is becoming second nature to me at all depths. It takes a lot of time and practice to develop these skills at that level. I'am still not there yet as I have not been diving with stages yet. That's the next level for me.

As far as DM or even instructor skills go, I have not seen much DM's or instructors with the level of skills needed to pass tech courses. The only ones who performed on that level were those who are trained and teach tec.