Rec Trimix

[TheRedHead]

Not that I'm considering this particular class, but my TDI instructor says that shallow Trimix is a bad idea because of how quickly you acrue a deco obligation. That seems in opposition to another agency's opinion. What do you guys think about Trimix or Triox at 80 feet?

 

[captndale]

The major problem with shallow water "tri-ox" use is that some users do not have the buoyancy skills to use it safely. Helium is a gas that is dissolved into the tissues very quickly. It also comes out of solution quickly. It is very important, when breathing mixes that include helium, that you ascend very slowly, 30 feet per minute or slower, and avoid "sawtooth" profiles. Most divers have a difficult time keeping their ascents under 60 fpm. That is why we are pushing "safety stops" so hard. Making a fast ascent while using a helium mix, even on a "no decompression dive," can easily and quickly result in decompression sickness.

 

[grazie42]

I guess it depends on your definition of shallow...
Adv. Rec. Tmx will let you go to 150ft, at that depth I think some He is a good idea and if you don´t plan on going much deeper than that, I´d say go for it!
I took it as a sort of "discover trimix" and it helped me make the descision to go for full trimix later...
If you don´t try it, you´ll never see the benefits...

As for dives in the 80ft range? For me, it´s not worth it, and the things captndale said about the level of skill needed is true. Triox is not as forgiving as nitrox so if you don´t have control, don´t dive it...you could get hurt...

 

[TheRedHead]

I'm probably going to take Trimix as my next class. GUE seems to advocate Trimix at depths where I would dive air nitrox. I don't recall hearing any arguments as to the disadvantages of diving Trimix at 80 or 100 feet. There are appear to be some real ones.

 

[grazie42]

I think the GUE thinking is that they won´t let you pass the class without the skills you need to do it safely...80ft is shallower than most agencies teach as acceptable levels of narcosis...ymmv...

P.S I saw that you´re going to fla, RH, I´d recommend doing the hydro atlantic. It´s a really nice wreck!

 

[Rick Inman]

I think the GUE thinking is that they won´t let you pass the class without the skills you need to do it safely...

I'm in the IANTD rec trimix class now, and buoyancy skills is an absolute requirement. The deeper stops aren't really "stops", but controlled ascents that take the proper amount of time. If you don't have the buoyancy skills to do this, you're not ready for HE, IMHO.

Which is why my IANTD instructor said that the best thing I did was take DIRF.

 

[lamont]

Not that I'm considering this particular class, but my TDI instructor says that shallow Trimix is a bad idea because of how quickly you acrue a deco obligation. That seems in opposition to another agency's opinion. What do you guys think about Trimix or Triox at 80 feet?

I've been following GUEs teachings that you dive 30/30 with the same NDL tables as EAN32 with 1 min stops from 1/2 max depth to the surface and i'm not bent yet, and haven't felt bad after diving. We'll do 25-30 mins @ 90-100 on 30/30 and get out with minimal deco. And 30/30 at 80 feet is a bit expensive but it gives you a very clear head, at 100 feet the beneficial effects of the 30/30 are noticable (at least up here in the cold dark PNW waters).

 

[TheRedHead]

I think all the tech agenices care about buoyancy skills but my instructor's point of view was: why incur a deco obgligation at 100 feet on Trimix when you can dive it on Nitrox cheaper and dive it within the NDLs or with minimal deco. He thought the idea of rec divers diving Trimix kind of screwy. And most people consider a 100 ft dive suitable for recreational divers.

 

[Kevrumbo]

I think all the tech agenices care about buoyancy skills but my instructor's point of view was: why incur a deco obgligation at 100 feet on Trimix when you can dive it on Nitrox cheaper and dive it within the NDLs or with minimal deco. He thought the idea of rec divers diving Trimix kind of screwy. And most people consider a 100 ft dive suitable for recreational divers.

Because you'll have a clearer head (less narcosis), and just as important, decreased work-of-breathing effort --A primary advantage especially if physically working hard or stressed. . .

 

[TheRedHead]

I'm trying to weigh the pros and cons here. That's all. I notice increased breathing effort at 130 ft with excellent regulartors.