Future of OC trimix

[Mr. Dooley]

After recently getting AN/DP certified via TDI, I was talking with a local technical instructor regarding additional courses advance my training. I inquired about trimix. I got a response that this instructor / shop doesn't teach trimix, nor do they have any plans do. With the cost of helium going up and rebreathers more affordable than they used to be, what's the point. The example I was given was a dive trip with a bunch of decompression dives with trimix . . . the cost of fills (assuming 200 cubic feet of back gas) could easily be more than the cost of a used rebreather itself. Fair point I suppose.

Interest for trimix training for me is to be able to go deeper more safely, and to continue my training as I enjoy the process. I don't have dozens of deep trimix dives lined up per se, but I could see myself getting the occasional fill for certain dives below 100 or 120. There's a wreck in my area that goes to 160 and I'd rather to trimix certainly than air for that.

That being said I DO believe rebreathers are part of my diving future. I've assumed this for awhile. But being told that I may as well just skip trimix and buy a rebreather was a bit of a surprise, and financially I sure as hell wasn't planning on a rebreather purchase tomorrow. I'm just now completing my first tech kit and yeah, even with a bunch of used gear it's obviously a lot of money.

So I guess I'm just curious what folks' thoughts are. Given the price of helium and that there are more economical options to get into rebreather diving than there were in the past, is OC trimix going to sort of phase out? What trends are there currently in this regard, and where do you suppose it'll go?

 

[Whitrzac]

There is NO reason to do OC trimix before buying a rebreather.

If you're planing a rebreather, the sooner you get into one and diving it the better.

An oc dive to a 160 wreck around here would probably run $500 in gas, or more for a double dip.
RB is around $30.

 

[tbone1004]

I second the instructors opinion, no need to do OC mix unless you have to. The experience gained can be done at shallower depths with the right practice and you can always practice bailout ascents. I would not however stop doing OC dives at nitrox depths which many divers do.

 

[Marie13]

I was supposed to finish OC AN/DP/Helitrox this summer (didn’t finish last summer due to scheduling issues). My sources up to three hours away couldn’t guarantee they’d be able get enough helium or any. I know shops with a contract that are on a waiting list that has a three month back order. Some shops will only fill for CCR. I was talking about helium situation with my instructor and she recommended going CCR now. I was already ready and thankfully had most of the money in the scuba fund for it. Just moved around some other funds temporarily to make up the difference.

That’s why I won’t be finishing OC AN/DP/Helitrox and am going CCR this year instead of next year. I put down my deposit to get a spot in line a few days ago and my specific unit was ordered today. Probably won’t have it until late summer. They’re booming.

Just doing AN/DP without the Helitrox is not an option for me due to how badly I get narked at 130ft. It would be brutal, and frankly, dangerous at 145ft.

I have four 85s filled with 20/20 sitting in my living room. They were filled for class days last year that didn’t happen. I’m saving those for CCR Helitrox, which I hope will be next year.

There are sources of helium 5-7 hours away, but that’s just crazy. Better to go CCR now as that will be better than SM for my wreck diving anyway.

 

[doctormike]

Yeah. I may be wrong about this, but it's my impression that most people doing the sort of dives that would require trimix these days are diving CCR (most of the younger people, anyway). As helium becomes harder to get, the idea of just throwing it away with every breath makes less and less sense.

CCR isn't for everybody, and I wouldn't push it on someone who didn't have the mindset for it AND the ability to commit to enough diving to keep their skills up. But if you are at the point where you are going to do trimix tech dives, I thing that implies satisfaction of those criteria.

I wish I had gone CCR years sooner. If you are already tech certified and considering trimix training, and if you see CCR in your future, what's the point in waiting? Yes, it's more of an initial outlay, but if you are going to be a trimix tech diver, you are already going to be spending a lot. It takes a LOT of diving to give CCR the financial advantage over OC, but I don't think that's the reason that most people do it.

At least do a try dive and see what you think...

 

[broncobowsher]

Spend money to save money.

I've found diving in general to be much more enjoyable after switching to a rebreather. The added depth capacity is what I was originally after. Adding Helium was part of it. Never done a trimix dive before I did on the rebreather. And only on OC as bail out training. I plan to keep it that way. I'm cheap enough that when I want to brush up on bail out, I do it shallow with air.

I remember being in Truk. Helium was so scarce (regardless of cost) that only rebreathers were allowed to have access to it. On a mid level tech dive there was one guy on OC doing the dive on five AL80s of various air and O2, and he did keep up with us. End of the trip it was time to pay the gas bill. The OC O2 bill (air was free) was higher than our O2 and He bill combined, by about twice. And he didn't get to enjoy the deeper, more remote stuff either.

 

[Tracy]

I teach OC through Helitrox. After that, it is CCR. It just doesn't make sense anymore. Costs and availability are making it go way of the dinosaurs.

 

[formernuke]

I'm doing AN/DP and trimix all three, just started to first 2. My situation is different though as I'm not paying for the classes. I haven't decided on CCR though I likely will at some point. It's going to take a lot of saving though.

 

[broncobowsher]

I'm doing AN/DP and trimix all three, just started to first 2. My situation is different though as I'm not paying for the classes. I haven't decided on CCR though I likely will at some point. It's going to take a lot of saving though.

So you are not paying for the classes. Don't really care how you pulled that off, doesn't matter.

What are your plans for actually diving? You take the class so you can do dives, not just take training. Not much point in taking classes and never actually go use them after class is over. At that point who is picking up the tab?

This is where OC Trimix doesn't make sense. When the money is flowing out of your own pocket.

 

[formernuke]

I plan to do dives in the 100-130 range in OC trimix (not often) while saving for the breather.

And it's called GI bill.