[IanDennis]

Originally Posted by Mark Powell

You DO NOT need to dive to 45m to get experience with Adv Nitrox and Deco before Trimix. The course standards clearly state that one of the qualifying dives needs to be deeper than 30m, but that can be 31 or 32m. Once qualified, If the diver really doesn't want to dive below 30m then they can then get experience in the 25m-30m range before going on to Trimix. If even a single 32m dive is more than they are willing to accept then they can combine Advance Nitrox, Deco Procedures and Trimix into a single course so that they never need to dive below 30m on anything other than Trimix. It's a long intensive course but is perfectly accetable under TDI standards (sort of sounds a bit like a Tech 1 course).One of the advantages of TDI is that it offers the flexibility to follow either path.

Mark- Obviously each course whether AN & DP or Triox has it own respective merits and qualities that will appeal to different divers. Most of the technical agencies can tailor a course as you describe- the timescales involved is usually the prohibitave factor however for the student.


Triox course standards take us to a maximum of 48m – as with any other course the student is given a foundation to build upon. Whilst they may experience diving to these depths under direct instructor supervision, the majority would then seek to build up their experience gradually prior to moving to the maximum limitations of the course.


Whilst there is greater skill involved in the use of Helium then by the time divers have completed the course they should be competant to complete such dives. As I have commented upon before Triox is an intermediate course and should not be considered equivalent to a Normoxic Trimix course.

Originally Posted by Mark Powell

There is no Triox course as such. TDI are of the view that if you are using Helium then you need all the skills of the Adv Nitrox, Deco and Trimix courses.

Guess we must agree to disagree there then