Man, y'all wanna make this complicated! And some of you just WANT to make it sound like it's a major deal to take a rEvo deeper than 100m.
- Every rEvo MOD1 class should include training on how to adjust the O2 reg IP to match your personal metabolism.
- The depth limit is based on what the IP of the O2 reg actually is. For the rEvo Apeks O2 reg, the factory says it is stable to somewhere around 13 or 14 bar, IIRC. They now also have the option for Mares regs and the Mares O2 reg supports a much higher IP. 25 bar(? I think?). So, you CAN setup your rEvo to handle much deeper depths than 100m on "automatic" without needing to do ANYTHING differently.
- For diving deeper than the limit of the O2 reg (however YOU have yours set), the simple answer is to plug in (to the Offboard port on the MAV) an offboard supply of anything from 50 to 100% O2. 50, if you're not staying that deep for very long. O2, for sure, if you are. When you pass your depth limit, you are flying the unit manually - just the same as any other manual CCR on the market. A skill that you should have developed during MOD 1 and (should have) practiced plenty more by the time you are doing 100m dives. If you are not capable of flying manually RELIABLY, you shouldn't be doing 100m dives.
- If you are ready to dive to 100m, you SHOULD already be VERY solid on constant monitoring of your ppO2 (even if you normally let the setpoint controller actually run your O2 for you). If you are, then when you go below your unit's depth limit, you will notice the ppO2 starting to drop and know that it's time to start running it manually.
- At that depth, it's very likely, your time below your unit's depth limit won't be very long. You will only need to add O2 to your loop manually a very few number of times.
- If you're diving that deep, it would certainly not be a bad idea to carry an extra cylinder of offboard O2. All the same reasons an OC diver could lose a cylinder of deco gas apply to your O2 cylinder on your CCR. You *could* lose the O2 in that cylinder and, if you do, it sure would be nice to have another supply you can plug in and use while staying on the loop.
- There was some talk upthread about an orifice in the MAV. I *think* really old rEvo units (maybe even back to rEvo II units, versus the rEvo III, which has been "it" since something like 2009) did have the CMF orifice built into the MAV itself. But, they don't anymore. Modern MAVs do not have any orifice in them, so no complications there.
- For the posters talking about picking a dil that gives a ppO2 of 1.2 at max depth and then just doing dil flushes when your ppO2 drops too low: Maybe if you are running an offboard AL80 for your dil. Maybe. But, if you are using a more normal 3L cylinder for your dil, you are going to run out of dil on probably your first full dil flush at 100m. Maybe your second dil flush. That is assuming you are also using your dil for wing inflation. Flushing your loop uses a lot of gas. A rEvo III Micro with CE counterlungs has 5.5l lung volume. At 11 ATA, flushing the loop with dil... well, you can do the math. If you're conservative on your dil flushes, you won't get a really full flush, but you might get 3 or 4 at that depth? Bottom line: That is just not the right way to do it. Bottom line 2: If I'm having to tell you this, then you should take (or re-take) a MOD 3 class before you attempt any diving past 60 or 70 meters.
There really is no NEED to mess with changing the unit to an eCCR. That would take away a big benefit of the rEvo for a very, very small benefit on a (I'm assuming) very small number of dives.
There is no NEED to mess with the O2 reg's IP.
If you have a bog stock rEvo and want to dive to 300' or deeper, all you need to do is have a cylinder of 50 - 100% that you can plug into the offboard, then fly manually at depth. Simple. There are a LOT of things to overthink on dives like that
, but how to setup your unit because of the CMF and O2 reg IP is not one of them.
I have taken mine past 300 several times and to 350 once, with no mods to the unit itself. I am personally not ready for 500', but my unit is ready to go there, setup just like it was for 350. Do I wish it could go to 500' without needing to fly it manually? Well, yes! Sure I do. But, it's just not that big a deal (to ME) to fly it manually on those really deep dives. It's a tradeoff I am happy to make in exchange for the benefits I feel like the other parts of the rEvo design give me.
Disclaimer: rEvo is the only unit I am certified or have any real experience on. I love my rEvo. But, it certainly could be that I would like another unit better if/when I get time on one. Time will tell.