Standard gasses

[broncobowsher]

After learning ideal gasses in training, I've simplified my (DIL) gasses.
Air to 100' (pool diving)
18/35 100-150'
14/45 150-200'

I can have bottles filled and sitting around. What will I be doing this weekend? 130', OK that will be the 18/35. Already have that ready to go. Gas already programmed, just switch it on. Planning a 180' with backup plans for 140', just take the 14/45 as it will work for either.

 

[jont2]

What ease of blending gets you to 18/35?

18/45 makes more sense.

 

[LFMarm]

I have also simplified down to 3 std gases in 2 sidemount sets (for CCR with dilout):

• 21/35+50/0 for dives shallower than 50m/170ft
• 10/70+21/35 for dives in the range 50m/170ft to 90m/300ft

I am not using air anymore unless it's the only option; in that case my diving will be limited to 30m/100ft (which is plenty when diving with rest of the family).

 

[rjack321]

• 32% down to 100ft
• 25/25 caves or down to 120-130
• 18/45 the universal dil down to 200
• deeper than 180 is 15/55 down to around 250ft where the deco to value ratio ceases to be fun

 

[inquis]

10/70+21/35 for dives in the range 50m/170ft to 90m/300ft

Presumably the 10/70 in order to hit a dil PO2 of 1.0 at max depth? Much of the cave diving community likes running a dilout matching the setpoint, and I've found I also prefer it for OW. It'll still drop a high PO2 pretty fast, but the lesser impact for depth variations (the normal use case) is pretty nice. Just something to consider.

 

[rjack321]

My only "yeah no thank you if I can avoid it" is 10/50. I've been on a charter that banked 10/50 though and in a when in Rome spirit I rolled with it. It's ok down to 200ft ish but really works the solenoid like crazy and its way too light on helium for anything deeper the 200ft for me.

 

[crofrog]

Once I had my RB, I was able to do that half mile dive up the gold line at Ginnie because I only needed to carry 2/3 the gas for bailout as I would have needed for the same dive on OC. For those who don't know, that's about 90 min in, 90 min out and 90 min deco at 20'. That's pretty cumbersome on OC, and I would feel rushed on the exit as I'm breathing the second third of my gas.

What PO2 and GF high do you run for that dive? That seems like a lot more deco than most people do (not critiquing just asking)?


I'm sure there is less to carry with a rebreather but is it really that much less? I'm guessing you're still carrying 2 bailout tanks, and an o2 bottle plus the rebreather and those dive times seem pretty close to what you can get out of a 2 bottom stages dive and an O2 + double 130s

 

[LFMarm]

Presumably the 10/70 in order to hit a dil PO2 of 1.0 at max depth?

I typically plan for 1.2 at the bottom; 10/70 is my 90m/300ft gas and is limited by density (5.2 g/L) rather than pO2 (1.0 at 90m).

 

[inquis]

I typically plan for 1.2 at the bottom. 10/70 is my 90m/300ft gas.

Wouldn't 12/65 be the better choice, then? Especially considering you're using it on dives as shallow as 170 ft? [edit: and it gives the target 1.2 at 90m]

 

[rjack321]

What PO2 and GF high do you run for that dive? That seems like a lot more deco than most people do (not critiquing just asking)?


I'm sure there is less to carry with a rebreather but is it really that much less? I'm guessing you're still carrying 2 bailout tanks, and an o2 bottle plus the rebreather and those dive times seem pretty close to what you can get out of a 2 bottom stages dive and an O2 + double 130s

Yeah I can swim all the way to mainland and spend 2 hours back there and have basically 35mins of (50/70 GF) deco on 25/25 and Sp of 1.2. 90 minutes is crazy amounts of deco for anything exit side of the Hinkle