Question Tri-Mix regulator questions

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Rebreathers are great but you have to make a big commitment to learn and master the box. It's not something you take lightly. You need to commit a lot of money to buy the box and for GOOD training; $10k + $2k. You need to commit a LOT of time (a whole year at least) to perfecting it and getting your hours on the unit***. You must commit to lots of reasonably deep ascents -- of the 40m/130ft range.

Moving to a rebreather is nothing like all of your recreational training thus far.

The advice I proffer to people asking this question is firstly you must be sure you want to commit the time and effort, secondly that you must have excellent existing core skills (buoyancy, trim, finning). It also enormously helps if you've already achieved ANDP (Advanced Nitrox & Decompression Procedures) as rebreathers use stage cylinders and they really facilitate deeper, longer and decompression diving.



*** Hours on the unit. IMHO:
  • 25 hours - still a novice
  • 50 hours - waiting for it to bite you, beware of complacency
  • 75 hours - beginning to get in charge of it, buoyancy skills are back
  • 100 hours - intermediate skills, but beware of the unit as complacency will kill you!
 
I’m fortunate that locally, I pay about 1.60USD/cuft + O2 at the shops, but I do my own blending, so it’s down to 0.60USD/cuft…. Minus yearly cylinder leases, booster setup and maintenance and a relationship with the owner of a dive compressor



There is some merrit to debate on CCR..

If you are REGULARLY doing trimix dives, then it can POTENTIALLY save you money down the road (<5 years)., but it also brings more things… more maintenance, booster, etc.


Doing some quick math, recreational dives (no accelerated deco, no helium) you won’t recover your costs vs OC..

Once you add in helium and OC deco mixes, you start seeing $50-100 savings per dive in the normoxic trimix range… still takes a while to recoup 10k+ of CCR cost…


I’m a fan of people taking OC normoxic training first, then moving to CCR….


_R
 
It depends on your geographic location. In California, expect to pay $2.00cft. I believe they pay the same near the Great Lakes region. Pesonally, I have a spare tank. I have my shop transfill the trimix into this spare tank while they perform yearly service on the tank and the manifold.
thats smart! im luckily 20 min from my local dive shop, and i love them!
 
I’m fortunate that locally, I pay about 1.60USD/cuft + O2 at the shops, but I do my own blending, so it’s down to 0.60USD/cuft…. Minus yearly cylinder leases, booster setup and maintenance and a relationship with the owner of a dive compressor



There is some merrit to debate on CCR..

If you are REGULARLY doing trimix dives, then it can POTENTIALLY save you money down the road (<5 years)., but it also brings more things… more maintenance, booster, etc.


Doing some quick math, recreational dives (no accelerated deco, no helium) you won’t recover your costs vs OC..

Once you add in helium and OC deco mixes, you start seeing $50-100 savings per dive in the normoxic trimix range… still takes a while to recoup 10k+ of CCR cost…


I’m a fan of people taking OC normoxic training first, then moving to CCR….


_R

The OC twinset fill price answers you've seen on here aren't particularly accurate.
  • The first fill costs the full amount
  • Subsequent top-off fills are cheaper because it's not a full fill, just a top off. At least a third will be left over
  • You do need to buy a second (third, forth...) twinset so that you've the flexibility to be gassed up for deeper dives, but have an air/nitrox filled one for shallower dives
Finally... Standard gasses are ridiculously expensive and few people, except those who follow the rools, will dive those gasses as they'll dive the right gas for that dive.

Example: 45m/150ft dive. The "true" gas would be 21/35. The pragmatic gas is 25/20 or thereabouts. Even a 'bit' of helium to knock off the narcosis would help: 25/15 or even 25/10. Those mixes are far cheaper than a standard mix.

It's all down to your personal disposition to narcosis, plus the type of dive (is it a pinnacle dive, much work at depth, need your head screwed on...).


I think it more then just "potential" saving is more guaranteed savings and it happens a lot faster then 5 years. More like in a couple months

I know I was talking about sub 100m dives ok so maybe thats not a realistic normal dive for most. Lets pick a simple 60m-70m range dive. Below is pretty standard type dive I do 2-3 times a week, I attached a quick multideco plan below

For simplicity lets use a 17/45 bottom gas, 50% and O2 for deco. Also lets assume diver is fit with a low SAC rate of 12l/min bottom phase and 9l/min deco phase.

In Indonesia user price right now for He is about $0.18 /liter and O2 is $0.03/liter

He: 2142l x $0.18 = $386
O2: 1335l x $0.03 = $40
Total: $426

$426 is not the fill price this is strictly just the cost of gas you would consume does not include any extras for a full tank fill plus rule of 1/3rds or whatever your using.

Normally do this dive 2-3 times a week so that is $1,278 in gas every week if I was on OC

On my rebreather I am spending about $120 per week.

$10,000/$426 = 23 dives

In 23 dives you would pay for an expensive rebreather. Going on 23 dive is nothing this would happen alot faster then 5 years. For me this would happen in 2-3 months of diving.

But lets say you dont dive that often maybe 35 dives a year. So that is 35 x $426 = $14,910
If you do that for 5 year in a row. $14,910 x 5 = $74,550

5 years of OC trimix diving at only 35 dives a year is a $74,550 gas bill. And that is for infrequent diving, 35 dives a year is nothing I know there are lots that are doing way way more that that. I know I probably average about 100 trimix dives a year (and even this is not that many compared to instructors). Image what that OC gas bill would be

Lastly this $10,000 price tag for a unit is for top the line new unit. Remember you can buy used also. Just noticed 45min ago someone posed an SF2 for $4,500 SF2 ECCR for Sale
and befor that there was a JJ for $7,300 For Sale - JJ CCR

1644095461087.png
 
There’s other benefits of CCR diving too.
  • Flexibility —gas selection is far less critical. You can use a far more hypoxic mix and the unit will always mix the optimum PPO2 for the depth thus standard gasses can be used (E,g. for 70m to 45m use 14/55 or richer). If the dive is deeper or shallower, no worries.
  • Stress — Bottom gas volumes aren’t an issue should you get "delayed" on the bottom. Sure, you pay for the overstay with additional decompression time, but you don’t run out of gas.
  • Less kit needed — Multiple dives on same gas or scrubber means you don’t need to carry endless cylinders for consecutive dive days. At the worst just change the scrubber.
  • Resilience — should things go wrong there’s more options available: it’s not all bailing out to open circuit. Can run the unit manually, use offboard gas supplies, run as semi-closed rebreather, etc.
  • Silence — stealthy (not scaring the fauna)
  • Warm and moist breathing gas for comfort.
  • Lighter kit especially for hypoxic deep diving
  • No bubbles— very important for fragile overhead environments such as decaying wrecks and mines where bubbles dislodge the "roof" or rain particulate down on you
  • Gas availability— with three twinsets as gas banks (oxygen, rich trimix and air) you can do many dives without visiting a gas supplier. Saves a small fortune in cylinder testing fees.
This list can go on a lot more.
 
if i ever do, it will be maybe 15-18 years in the future, not anytime soon.

Gill transplants might be a reality by then :D
 
Wow Wow Wow! Just Wow! A simple question about regulators has uncovered such a wealth of practical information and knowledge about diving… I am going to have to come back to this thread after I finish reading up on decompression theory and all the other the textbook stuff.

Thanks guys for making this forum so enlightening as always! 🙏🏽🙏🏽
 
Wow Wow Wow! Just Wow! A simple question about regulators has uncovered such a wealth of practical information and knowledge about diving… I am going to have to come back to this thread after I finish reading up on decompression theory and all the other the textbook stuff.

Thanks guys for making this forum so enlightening as always! 🙏🏽🙏🏽
Hopefully it’s highlighted that recreational/NDL diving is a fraction of the skills, planning and techniques required for technical diving.
 
I’ve done a few rebreather dives. Some of them pretty interesting.
Dude, snoozing 4 hours on the log at Eagle's Nest is anything but "interesting"
 
I want to dive with tri-mix, eventually, and wanted to make sure that a regulator will be able to work with tri-mix. I see them advertised as able to take up to 40% o2, but does helium play a role in this? thanks!
Regs fine with trimix - if you're using mix, you're diving deeper therefore probably need a stiff nitrox to accelerate deco, this reg will need to be in O2 service. Most regs can be cleaned and serviced for O2 - if you want the green plastic add a a hefty sum to the price (green plastic must be really expensive lol).
CCR or OC - depends how much deep diving you do - truk - my mate used 20/20 - I used 18/36 - my bill was cheap his was eyewatering and only did morning dive on trimix. However, service costs, purchase cost, training costs, oh and don't forget how completely fed up you'll be when you're faffing about with your CCR and your mates are shaking their heads and ready to go in their twinset rigs- having said all that, I love my CCR
 
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