TDI Adv EANx/Deco VS IANTD Adv Rec Trimix - why always TDI?!

[Bardo]

Ok, here's an interesting point of discussion for ya...

I've noticed that most budding 'techies' on here seem to choose the TDI Advanced Nitrox / Deco Procedures courses over the IANTD equivelent, Advanced Recreational Trimix. Simple question - why?

From what I can see, the only real limitation of the IANTD ticket is that you're limited to a maximum of 15 minutes of deco but you do get access to two very useful 'recreational' trimix mixes - tx28/25 and tx32/15 - which provide something that the TDI courses cannot - that is, a narcosis-free head equivelent to just 20m at the ticket's maximum depth of 48m. Surely access to trimix in the 30-48m range is more useful than an 'unlimited deco' ticket?

So with this in mind, why do you chaps choose to go down the TDI route instead? Other than the very valid argument about the quality of the instructor being more important than the course, what is it about Adv EANx/Deco Procedures that makes it a more attractive option for some?

BTW - Let's assume, for the sake of argument that both agencies' courses are taught by equally capable instructors so please don't just respond with the usual 'Because XXX teaches it'. Let's assume that XXX can offer either course and therefore take this factor out of the equation!

[deepestandy]

Trimix is a bit cost prohibitive on O/C for some.

[Lou]

I would say it was not more nor less than the TDI course is better known. Probably why I did it

[Reikimaster]

if i had known i could get a rec trimix ticket, i would have probably gone for that if i has thought about it.

but the course and the inst were there at the right place right time etc (ive just done my IANTD CCR course so not fussed about the acency)

[JamesW]

And its down to the Instructor.

[Scubee]

I don't think I was aware of the ticket, but I wouldn't have done it anyway because of thos two limitations. I can't see me being interested in a limited trimix ticket, a limited deco ticket. Going down the TDI route gives more flexibility in relation to the diving I want to do int he short and longer term.

I do think that just like you can develop a tolerance to alcohol, it is possible to develop a tolerance to narcosis. The shallower you start using trimix, the more reliant on it you become. Then it starts getting prohibitivly expensive.

[Mal Bridgeman]

When I got into this sort of diving I was very much inspired by Garf's AN & DP course write up so I chose Mark to do the same. Mark was very helpful giving me a lot of good advice, not just about the course but my diving objectives in general.

I did some deep air dives and really didn't like being so incapacitated. I come from the school of thought that believes that lower order mental processes may adjust to narcosis but the higher order mental processes, like decision making, do not ..... so my progression to Trimix was inevitable.

I chose TDI again because that was what was on offer from the instructor I'd chosen.

I did an IANTD gas blending course and was as unimpressed with the literature as I was with the TDI literature

If I knew then what I know now .... I'd have gone for GUE straight off, though.

HTH
Mal

[deepestandy]

The diving I do on an almost weekly basis is on air and in the 50m range and I have to say the narcosis I encounter on air at these depths is noticeable but manageable (for me anyway). I think the TDI adv EAN/deco prod course is just a little more versatile.

A logical step from here is obviously trimix oc/ccr, I think it might be a little too large a step for some, as well of the cost implications.

What do you pay for a Twin 12l fill of tx28/25 or tx32/15?

Andy

[weazelz]

I'm taking TDI AN+DP with Mark Powell in two weeks, so I'll answer with a pre-course viewpoint, rather than a hindsight-enhanced view

my current plan is to do a year or so of nitrox diving to ~40m & then do a normoxic mix course. I don't anticipate ever doing hypoxic mix on OC, I would probably go to a CCR if I wanted to go that route

leaving aside the choice of instructor, I would have been happy to take either PSAI or TDI AN+DP, or indeed BSAC ERD, as they are all very similar courses - unlimited accelerated deco, ticket for 100% - but I chose TDI because it is probably the most widely recognized agency of the three

I did look at IANTD Adv Rec Trimix but I was put off by two things

Originally Posted by Bardo

From what I can see, the only real limitation of the IANTD ticket is that you're limited to a maximum of 15 minutes of deco but you do get access to two very useful 'recreational' trimix mixes - tx28/25 and tx32/15 - which provide something that the TDI courses cannot - that is, a narcosis-free head equivelent to just 20m at the ticket's maximum depth of 48m. Surely access to trimix in the 30-48m range is more useful than an 'unlimited deco' ticket?

- 15 minute deco limit
I'm doing this on 50% on my BSAC Adv EANx ticket already. if it had been 30 mins then fine

- tx28/25 & tx32/15 - 48m limit
I don't get this - ppO2 at 48m on tx28/25 is 1.6bar, is this what they're recommending? or that nitrox should be used from 40-48m or is the ticket really for tx25/XX?

I think my ideal course at this level would be a 45m depth limit with unlimited deco, single deco mix to 100% & access to tx25/XX. if the IANTD course was a ticket for tx25/XX, then I think that might have swung it for me over the AN+DP courses

~andy

[warmwaterdiver]

Originally Posted by deepestandy

What do you pay for a Twin 12l fill of tx28/25 or tx32/15?

in twin 12's, would be about £20/25 for 28/25, £15/20 for 32/15, depending on local cost variations