Opinions Wanted: "Techreational" Trimix Diving

[Reg Braithwaite]

I'd like to get people's full-on opinions about diving hyperoxic trimix on dives that are within NDL/Minimum Deco limits. I know we have a good time arguing about labels, so feel free to discuss what you think this should be called, up to and including stroke-tastic or dumb.

A few agencies offer training in this practice, including GUE and UTD, who offer it at the top end of their "Recreational" training progression, and IANTD, who offer it as "Recreational Trimix" (they confuse things by also offering "Advanced Recreational Trimix" which is actually an intro to tech type of training).

The curriculum of my IANTD Recreational Trimix course went into the characteristics of He mixes, re-covered most or all of my recreational nitrox training, the importance of gas planning, and the use of tables to determine stops. The skills training focused on performing good stops in the water column and handling emergencies at depth. Namely, an out of air swim and donating gas to an out of air diver, both under 100'.

I may have missed a few things, but I'm sure you get the idea: It did not go into decompression diving, doubles, stages, or deco bottles. Although in theory it did not train how to dive in an overhead environment, in practice the message is that diving 25/25 means you have a deco obligation and therefore you must be able to solve certain problems in order to make your stop or stops, but your team is the only resource you are trained to use in this course.

So just for discussion...

• Is this technical diving? Or is it advanced recreational/NDL diving?
• is there value in this kind of training or is it a waste of time?
• Is this dangerous? Does it lead people into situations withpout the training to handle problems?
• Is this a luxurious waste of money and He?

Thanks in advance, all opinions welcome!

 

[Jonny boy]

Technical training is normally (in my mind anyway) classed as any of the following (onbviously not an exclusive list) Overhead, Decompression, Stage, Multi-gas etc so if your doing any of these activities whilst diving then i guess you could call the course technical. Most people that i have spoken to have said that below 30m Helium is a welcome addition, infact at least 1 of my friends wont dive below 30m on anythng other that Trimix (although we do have some of the cheapest Helium in the world!)
I cant see how this would be dangerous, in my mind the instructor will perform something of a 'screen' on potential course candidates before offering the course to them thus hopefully avoiding and un-qualified students sitting the class. Obviously we all know that Helium off gasses alot quicker than nitrogen so we have to be a little careful with our ascents, but the class should highlight this and a little common sense and a well structured course should help avod any of these potential issues.
This is just my simple, probably wrong view

 

[JeffG]

I would lump it into the advanced recreational/NDL diving section.

As far as being a waste of time and/or gas. There is not that much of a need for it, but there are a couple scenarios where it can be of use. (Some deeper cold water dives where it would be nice to have a clear head. Especially if I was poking my head into a wreck)

So it could be a useful tool in the tool bag, but you might not really need to use it that often.

 

[SailNaked]

NVM.. more

 

[netmage]

While I was still diving single tank OC on a regular basis, I would often have the shop mix a little 32% and 21/35 together for some of the deeper drops, i.e. Jim Atria & Rodeo 25

It would end up somewhere around 30/17 or so, just enough to take the edge off in the 130-140' range, but we'd always do a few minutes of hang time... As long as we were back on the boat in the 45-55 min time frame all was well..

 

[netmage]

NVM.. more

You should of kept it.... you are right...

The problem is people are not wanting to do the practical dives\time between the 'traditional' steps of training and instead doing all their diving with the instructor or on such an infrequent bases, the incremental steps typically covered by either experimentation on your own, or under some sort of mentorship are totally bypassed...

Thus the full mix student showing up w/ the minimum # of dives, vs. well over double.

 

[Reg Braithwaite]

As far as being a waste of time and/or gas. There is not that much of a need for it, but there are a couple scenarios where it can be of use. (Some deeper cold water dives where it would be nice to have a clear head. Especially if I was poking my head into a wreck)

I actually got it specifically to use on a return to the Forest City (135' to the stern rail), but by the time my vacation rolled around I didn't feel the rest of my skills were in place so I didn't do any deep cold water diving.

I've also heard this type of mix has applications for shallow dives in hi flow caves. I don't know if that's a breathing effort thing or if there's some sort of effect on CO2, I haven't any cave training.

 

[Sloth]

.... there is a bunch of stuff to learn in caves, not so much diving with a different gas in 130 or 150 or 190 ft of open water, do we really need to have 3 separate classes to learn to go an additional 50 ft in 10ft increments?

The physiological and psychological differences between a rec dive to 130 and a tech dive to 190 are huge.

Trying to progress from rec to deep tech in short period of time in less then the classes most agencies do would be extremely difficult.

Doing a recreational trimix class might be overkill but I think it is beneficial to break up deco diving training into bite sized pieces.

 

[Reg Braithwaite]

NVM.. more

Ok, I'll bite, NVM means... ?

And sir/madam, would you care for milk, sugar, or cream in your coffee?

 

[shoredivr]

I'd rather spend the money on a technical trimix course: more options to use it.