Musings of a Nitrox diving intending to go 'Mix

[Genesis]

Hi folks;

I'm a very active (over 100 dives in a year) diver who mixes his own Nitrox, dives into deco on purpose, does overheads, and lives in a place about to get (we hope!) an Aircraft carrier with depths that will eventually lead me to want to dive 'Mix.

Ok, so which way do I go here?

What am I talking about?

CCR - or OC?

Now, with the exception of spearfishing (which is illegal in Florida on a RB) the rest of my diving would appear to benefit from a CCR. I currently dive doubles, and they're heavy. If I start to add stages or deco bottles, they get real heavy. The "ready to dive" config of most CCR RBs I've looked at is lighter than just my set of doubles - and that's the complete kit, including harness. I also shoot video, and the lack of bubbles I'd think would promote a LOT more contact with the fauna of the ocean.

While I'd have to carry a separate bailout bottle on some deeper dives, I still suspect the weight equation favors the CCR. The gas cost issue definitely does, even today, and as He goes up in cost (and it will!) this will get even more extreme. Yes, there is the 'sorb cost, but that's balanced by greatly reduced gas expense.

There is also the comfort factor (no more dry, cold inhalations) which likely would have a significant impact on overall dive comfort and warmth.

Any thoughts? Comparisons between the different CCR RBs out there? What is the REAL cost (investment), split between training and machine, required to "make the jump"?

 

[caveseeker7]

Comparisons between the different CCR RBs out there? What is the REAL cost (investment), split between training and machine, required to "make the jump"?

The Dec issue of IANTD's Nitrox Diver, which should be shipping now, has a comparison of all current production models. AFAIK the Halcyon RB80 comes up short as IANTD couldn't get their hands on one. Available through IANTD and their facilities.
Ron Micjan also has a comparison on his page, as well as teardowns of several different models. http://www.tmishop.com/

If you get a finacial benefit out of using a CCR depends how much mix you dive. Aside from absorbant, you also have O2 cells to buy (about $220 annually), probably want a computer that can calculate constant pO2, and then there are the unit itself and the training for it. It adds up rather quickly.
Training should be anywhere between $1200 and $1800, at least around here it is. CCRs start at $4600 for the KISS and go up to around $8000.

When you compare prices pay attention. The KISS for example doesn't include the sensors or a bcd, you have to supply both. The Megalodon also lacks the bcd, and the ADV is optional.
The Inspiration and Prism come fully equiped and ready to dive. Just add sorb & fill the tanks. The former offers an ADV and larger wing options at extra cost.

Availability is another issue, KISS and Inspiration are readily available. The Prism takes about 16 weeks, the Megalodon also several month (last I heard was 5-6).

You shouldn't have problems finding instructors for any of those rigs in FL.

As for the pros and cons of each one just read through the threads, there are plenty detailing each model.

The only viable SCR alternative is the Halcyon RB80, which cost as much or more as any of the CCRs, and you have to be GUE trained (DIR-F & Tech-1) to get certified on it.

The RB80 will not give you the benefits of diving with a set pO2, extended NDL and reduced deco times. Aside from gas savings the biggest advantage of using a CCR.

Add-ited: Also consider that learning to dive and getting proficient on a CCR is going to set you back a year or two. It's a different way of diving, you'll have to re-train yourself for the RB, which takes time. You have to be humble and take that seriously, and won't be diving mix on the CCR any time soon.

 

[flw]

I'm not sure you can justify using a rb on cost alone, unless you are doing a huge amount of gas diving, very few do sufficient, even in the UK where He is more expensive.
In terms of keeping your own O2, remember you need higher pressures than you do for pp blending of nitrox, so tend to dump cylinders earlier unless you happen to have a booster, all of which adds cost.
None of the units around are perfect, all have their quirks, spares are easier to get for some than others depending on where you live - in the UK at least ambient pressures customer service is second to none.
For me the big advantage to a rb is I have an ideal gas for whatever we decide to do, our shores drop off quickly, and with a weather change our site depth can be 40 shallower or deeper than originally planned. He is also a complete pain to get shipped up here. I think there is a cut-off somewhere around the 80m mark, where I feel safer on cc than oc, other's opinions may vary on that though. I can also use a high he on every dive, and feel better, albeit subjectively.
If a rb is working properly, and everything goes according to plan, it is very easy to end up exceeding your capabilities very early on - I did this, happened to get away with it, but it doesn't make it sensible.
Costwise is probably different in the UK, lime works out between £55 and 75 for 20kg, I may only get 8 or 9 deep dives out of that much, for shallower stuff it works out far cheaper. Training costs, can't remember, think it was about £5-600 but that was 2 years ago, I was already oc trimix trained, and never got round to doing cc trimix training as well, so add on the same again at least. Cells last around a year, 3 plus a spare at £50 each. Most spares are cheap(ish) but you need a fair number for offshore diving/trips - one of my buddies accidentally dropped the scrubber overboard when emptying it out, which was pricey.
Would I make the same choice again, I think so.

 

[padiscubapro]

Hi folks;

I'm a very active (over 100 dives in a year) diver who mixes his own Nitrox, dives into deco on purpose, does overheads, and lives in a place about to get (we hope!) an Aircraft carrier with depths that will eventually lead me to want to dive 'Mix.

Ok, so which way do I go here?

What am I talking about?

CCR - or OC?

Now, with the exception of spearfishing (which is illegal in Florida on a RB) the rest of my diving would appear to benefit from a CCR. I currently dive doubles, and they're heavy. If I start to add stages or deco bottles, they get real heavy. The "ready to dive" config of most CCR RBs I've looked at is lighter than just my set of doubles - and that's the complete kit, including harness. I also shoot video, and the lack of bubbles I'd think would promote a LOT more contact with the fauna of the ocean.

While I'd have to carry a separate bailout bottle on some deeper dives, I still suspect the weight equation favors the CCR. The gas cost issue definitely does, even today, and as He goes up in cost (and it will!) this will get even more extreme. Yes, there is the 'sorb cost, but that's balanced by greatly reduced gas expense.

There is also the comfort factor (no more dry, cold inhalations) which likely would have a significant impact on overall dive comfort and warmth.

Any thoughts? Comparisons between the different CCR RBs out there? What is the REAL cost (investment), split between training and machine, required to "make the jump"?

Genesis,
Switching to an RB can be an expensive proposition.. If you do lots of deep dives it pays for itself quickly.. I'm doing well over 100 mix dives a year, even on OC at only $80 a dive for gas (usually more) it pays for itself each year.

RB diving is not for everyone, if you are one of those people who don't pay close attention to their guages, you aren't a good candidate, but if you pay attention to detail a RB just might be for you..

The greatest advantage of a CCR is that you can always dive a mix that has the optimum Oxygen content, you can dive a rich He mix with very little cost.. I have multiple sets of diluent cylinders, since it uses so little gas I don't dive air diluent.. My 2 mixes I use are 25%He, 20% oxygen, and 60%he, 10% oxygen.. The first I use on all dives to about 60m, the other deeper..

Depending on depth and if I am wet or DRY I get anywhere from 4-8 dives per diluent fill (I use independent suit inflation so less gas is needed for buoyancy if dry), My Oxygen use is approximately 2 cuft per hour of diving..

The most important thing many do not realize is that no matter how experienced you are on OC, it means squat.. You have to be retrained to unlearn all those bad OC habits.. People can easily exceed their training, you get spoiled by the "unlimited" gas supply.. Most divers on oc would probably do a 20-30min bt for a 60m dive, On a RB its more likely 60minutes.. The required decompression is pretty long and in the event of some type of failure your skills must be up to getting you out of trouble.. Just bailing to OC is usually not the correct choice..

Training is not cheap.. Good training is time intensive and I would beware of anyone offering discount training.. Training also has to be spaced out to allow the proper experience between levels.. A student of mine who takes the entire sequence from CCR diver through Trimix CCR would run around $4k for training (more if they don't already have Technical OC certs).

as for maintanance..

In the US most of us use generic teledyne R22Ds on Inspirations, MEGs, KISS ect.. They run around $75 each.. Those with Inspirations who chose to use APD cells R22-BUD are $125 each.

SORB prices vary dramatically, I have paid as little as $100 to as much as $200 for a keg of Sofnolime 812 (about 8 fills), or $90 for sodasorb 612 (RW. Grace) about $90 a keg (6-7 fills).. When I tarvel sometimes I am stuck using sodasorb 408 its only about $75 a keg