OC to CCR: After Trimix? Or after Adv Trimix?

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Master oc technical diving. Multiple bottle management, gas switching, dive planning. Then add in the rebreather. When it breaks you need to be a strong oc diver, there's a fair chance that you'll be mentally compromised in some way if that RB breaks.

This.
 
Donning my CCR instructor and hypoxic trimix instructor hat..

Stuart, as recently as two months ago your posts led me to believe you were worked up about doing a deco dive in the 150-160' range. I think you need to gain more experience and master OC technical diving in the ~150-170' range first before even thinking about a CCR or hypoxic trimix. Heck, you may even find you have no need for a CCR.
 
Donning my CCR instructor and hypoxic trimix instructor hat..

Stuart, as recently as two months ago your posts led me to believe you were worked up about doing a deco dive in the 150-160' range. I think you need to gain more experience and master OC technical diving in the ~150-170' range first before even thinking about a CCR or hypoxic trimix. Heck, you may even find you have no need for a CCR.

Worked up? I was definitely excited! And I definitely went through some mental gyrations to work out how to do gas planning for myself on OC with a buddy on CCR. But, I came to some conclusions about how to do it safely and I did the dives and all went pretty well. I did learn a couple of good lessons as I went. I've done more deco dives since then and felt like I learned more as I did them, too. I know I'm still learning and have plenty more learning to do at the level I'm at.

Also, I may not have made it clear but my plan is to complete Trimix over the next few months. Then take until AT LEAST late next year building skill and experience with normoxic trimix diving. THEN, over a year from now (at minimum) either pursue Adv Trimix on OC or start pursuing CCR.

So, maybe my possible move to CCR is so far down the road that my question is kind of silly at this stage of the game. But, I like to plan and have a clear roadmap for myself - even if it changes.
 
Master oc technical diving. Multiple bottle management, gas switching, dive planning. Then add in the rebreather. When it breaks you need to be a strong oc diver, there's a fair chance that you'll be mentally compromised in some way if that RB breaks.

I am asking this completely sincerely: How do I know when I have "mastered" OC technical diving and am ready to add a rebreather? I mean, I think that's really the nub of my OP. Can I "master" OC technical diving at the normoxic trimix level and then go to CCR? Or do I have to work up to hypoxic trimix and demonstrate mastery at that level before I go to CCR?
 
I'm glad to see you're learning as you're gaining experience. A c-card really is nothing more than a license to learn; that means you no longer need to have the supervision to prevent yourself from kacking, but that you will still continue to learn as you gain experience.

BTW, just enjoy the ride rather than planning the "next course" now.

As to the question of when will you know if you've mastered OC technical diving and are ready to move on to a CCR, the answer is you should know when it is time. If you wake up one morning and realize you need hypoxic mix or a CCR because you're ready for that next step, then you may be ready. If you never feel that way, then you're not.
 
If you have never done an OC dive to the depth you're bringing your CCR your bailout calculations are purely theoretical. If your bailout calculations are purely theoretical, in the event of an emergency bailout, you will have some queasy feeling knowing that you have never accomplished a safe ascent from this depth on open circuit. Resolving a dive emergency requires confidence and you only get the useful kind of confidence from having been there and done that through incremental experience.
 
I'm glad to see you're learning as you're gaining experience. A c-card really is nothing more than a license to learn; that means you no longer need to have the supervision to prevent yourself from kacking, but that you will still continue to learn as you gain experience.

BTW, just enjoy the ride rather than planning the "next course" now.

As to the question of when will you know if you've mastered OC technical diving and are ready to move on to a CCR, the answer is you should know when it is time. If you wake up one morning and realize you need hypoxic mix or a CCR because you're ready for that next step, then you may be ready. If you never feel that way, then you're not.
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I chose a slightly different time to jump from OC to CC after finishing my trimix class. I only did a few dives at the trimix level before realizing it just wasn't sustainable for me to continue diving OC. I was having to drive over an hour each way to get mix fills multiple times a week. That coupled with the cost of the gas made it worthwhile to switch to a rebreather. Only needing to go to a shop once a month to get tanks topped off was well worth it.

Do I need a rebreather for the dives I'm doing now? Nope, but switching for the ease in logistics was well worth it for me.
 
Stuart first of all I'm no rebreather diver (but interested in them) so take my advice with a grain of salt.

Although I think you are moving maybe a tad too fast you do have a sound head because you are asking good questions. You already know your goal, which is not rebreather diving as such, but diving deeper "monitor" style wrecks.

When to move to rebreather diving... that's a personal decision. I can just share where I'm at in my decision making proces.

I've done about 100 40-50m (130-170ft) dives on air before I started out with GUE and moved into trimix. So I was already well attuned to doing up to 30' of deco with 1 deco gas switch before I did normoxic trimix (T1). Then over the course of 2 years I did another 50 trimix dives in that range slowly extending my range. Then I did full trimix (T2), but at that time even wondering if I was "ready". (130 deepish dives in). Now I've extending in T2 range and to be honest it's going quite fast. 80 trimix dives in (30ish T2) with close mentoring I'm at ease in the 80-90m range (260-300ft) with 2 hours of deco.

I'm personally getting to a point where I'm considering breathers, because it's getting silly. I'm doing dives with a pumped up D18 to 270bar, a bottom stage, 3 deco stages and scooters, while all my mentors / buddies are diving RB80's or JJs. So range and logistics is one reason why I'm considering a change. The other is that of local network. I have quite some diver buddies who are on RB80/JJ so I have a readily available network to dive with. Finally it allows me more access to project dives.

Not yet bit the bullet but getting closer. In any case getting there is not a sprint, but a marathon. The monitor wreck is not going anywhere.
 
one thing that @stuartv and I have discussed that may or may not change some opinions on the speed is that a lot of these courses have been offered to him at steep discounts as part of instructor courses through the groups that he is diving with. One of the things I think is important to look at is whether a student has the cards or not, self regulating back to what you are comfortable with doing.

I.e. you get the opportunity to take full trimix because someone at the shop you associate with is getting an tech upgrade so you take the class basically for the cost of the gas fills and boat fees. If you are prepared for it skills wise, go for it.
After the class, just because you can go to 300ft, if you are only comfortable to 150-180, then stay there and gradually work your way up to it. At that point you have all of the skills required to go deep but you are choosing to hone them and gain real experience before you get there.

If you can restrain yourself for that, I personally have no problem with divers following a path like that.

In terms of the CCR vs OC debate, I'll stay out of that one since I am OK with a CCR being a lifestyle choice for diving and have no problem with people choosing to move to them fairly early so long as they still practice bailout conditions on a regular basis and actually dive open circuit on occasion to make sure their SAC rates are what they think they are, etc.
 
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