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dora farkas technical dive instructor
How to choose tech diving course?

TDI or PADI: How to pick?

We hear these questions many times. How to choose the best tech diving course? Which dive organisation shall I pick? TDI? PADI? GUE? IANTD? RAID?

I think is, first of all, make sure you choose the right instructor.

People have different styles, approaches, as well in teaching as in learning. For me, the most important, to make you as good diver as you can be! However, organisations do have different ways of teaching.

I teach technical diving in PADI and TDI systems, (*UPDATE 2020 December: From the end of January only TDI Tec courses will be available. I have decided to ditch PADI) therefore in this post, I’ll cover the comparison of these two dive organisations.

PADI has the usual well structured, standardized courses in Tech as in recreational diving. Clear objectives, every dive has certain skills assigned. The learning materials based on self-study, knowledge reviews and a multiple-choice test. So if you come from the PADI system, did previous courses there, no surprises.

TDI was the first organisation which created Technical diving courses. In these they give more flexibility to the instructors, just gave the list of skills which the student has to master, but which order and when it is up to the instructor.

Also, the learning materials are available in multiple languages, not only English, you can pick a paper book or eLearning version.

Also, you don’t have to progress by every 5 m 🙂


Usual path in TDI:

 TDI course flowchart

Advanced Nitrox and Deco Procedures combo (Up to 45 m) You can replace Deco Pro with Helitrox course –> Trimix (60m) –> Advanced Trimix (100m)


you start any technical diving course with TDI you need to be certified Advanced Open Water Diver from any organisation and have Nitrox certificate as well.




The minimum is 25 dives for the first level, however, I suggest to have a bit more. Make sure you feel confident with your buoyancy and general diving skills. Having your own equipment also helps you to be more successful in your tec course. You can take Advanced Nitrox course from 15 years of age, however for Decompression Procedures and above you have to be minimum 18 years old.

Consider starting with Intro to Tech, if you never have dived with twinset before. Picking sidemount setup is also an option if you already have experience in sidemount diving. I’ll cover the advantages and disadvantages of that setup in another article.

So if you pick this option, let say you start with Intro to tech.

First familiarize yourself with the equipment, learn about dive planning and improve your buoyancy. You won’t believe how changes in little things can improve your diving skills!

This course is also a great option if you already did some technical diving but feel like struggling (balance, trim, buoyancy). It can help to get over some difficulties or refresh your skills after a long break.

In Advanced Nitrox and Decompression Procedures courses, you get to learn actual staged decompression diving, teamwork, dive planning. Using nitrox up to 100% can accelerate your off-gassing greatly, and picking the right mixes for back and deco gas can improve safety. Until 45 m there is only one stage necessary.

Moving forward to TDI Trimix course, you get certified up to 60 m, using two stages. You have the option to take the Extended Range course which takes you up to 55 m on air, however, we usually don’t recommend this path. Deep air diving carries lots of risks and in technical diving, even a small mistake can lead to catastrophe.

After finishing the Trimix course, the next step would be Advanced Trimix. This is the last step regarding depth, on the course you can reach a maximum of 100m. We don’t always get there, depth is only a number. As we say, a rock can sink to the bottom of the ocean, coming back safely is the trick…

This was one option what you can choose when you progress in technical diving. Let me see the next:

Progress in PADI:

 padi tec flowchart

Tec 40 –>Tec45 —> Tec50 –> Tec trimix 65 –> Tec Trimix (90m) Materials are available in English, only in PDF format.

Prerequisites in PADI

To start your technical diver career with PADI, you have to be minimum 18 years old, have Advanced Diver, Nitrox certification and experience in Deep diving (either certificate or logged deep dives) To enrol in the Tec 45 course you will also need Rescue Diver certification.

This path

is easy to understand, since in the name of every technical diving course is the depth limit included. Compared to TDI there is an extra step, the Tec 50 course.

PADI has a similar structure within each course: start with a skill dive, then slowly progressing to deeper and deeper.

There are strict depth limits for each dive and certain skills to practice. This makes sure that you repeat each skill to a certain amount of times, however, sometimes it makes the course a bit rigid. Compared to recreational courses it is not that easy to cross over from other courses to PADI in technical diving, therefore if you started in one organisation, you can just keep up with the same one on your path, or repeat some levels to transfer.


Hope this article helped to answer how to choose tech diving course. In the end, it is your decision. Of course, both paths have pro and con, for my side whichever you choose, I’ll do everything to get the best out of you! Keep in mind, you buy the course, not your certification. That you have to earn.

Let me see what do you offer!


UPDATE November 2020

I have made my decision. From the end of 2020, I will offer only TDI technical diving courses. 

Probably you have got the feeling from my post which one do I prefer. Finally, I had the chance to drop PADI and it’s courses. 

I can not say, you should not ever take a PADI technical dive course. But for me, since I find it more enjoyable working with TDI,  it was no point to keep membership with both organisations.


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