PSAI Narcosis Management course - 73m on air

[ucfdiver]

I thought you guys were here to save me from myself and my instructor, and here you are recommending these unsafe mixes...

So now it doesn't need to be 'safe', just 'safer'?

So it's okay to break the rules, so long as you only break them a little bit?

Anyway, I think you get my point

How about someone posts the comparative runtimes, I really would like to see them

Arguing aside (I think we've all said our piece here), I'll post the results with various algorithms if you tell me what schedule/algo you'd like to see. I don't dive to those depths or have any interest in diving to them until I have trimix funds, so I can't comment on what deco I would actually do....but it'd give you a general idea I guess.

 

[Blackwood]

So now it doesn't need to be 'safe', just 'safer'?

That's exactly the name of the game.

There is no line in the sand between safe and unsafe. It's all shades of gray.

 

[Tortuga68]

Arguing aside (I think we've all said our piece here), I'll post the results with various algorithms if you tell me what schedule/algo you'd like to see. I don't dive to those depths or have any interest in diving to them until I have trimix funds, so I can't comment on what deco I would actually do....but it'd give you a general idea I guess.

Arguing aside, I would be really interested to see:

Runtime for 10 minutes bottom time @ 73m switching to EAN 50 @ 18m and EAN100 @ 4.5m (my runtime)

versus

Runtime for 10 minutes bottom time @ 73m on trimix plus whatever deco gas/stops would be appropriately used with trimix (I honestly have no idea)

I used decoplanner for my dive plan if that helps

That's exactly the name of the game.

There is no line in the sand between safe and unsafe. It's all shades of gray.

This is my point - what is safe? A lot of people have criticised me for using 1.7x PPO2, and I accept that, it's dangerous, no doubt. But then the same people suggested using 'safer' mixes that are also conventionally considered 'unsafe' but to "lesser" degrees?

 

[ucfdiver]

All VPM-B +2

Air w/o deco gas
Depth Time
24 1
21 1
18 1
15 1
12 2
9 3
6 6
3 9

Air w/ 50%
Depth Time
24 1
21 1
18 1
15 1
12 1
9 2
6 3
3 6

Air w/ 50% + o2
Depth Time
24 1
21 1
18 1
15 1
12 1
9 2
6 2
3 4

Just to compare, here's 21/45 with 50%+100% so you can keep your same ppo2 but get the limited narcosis, since I *THINK* this is what you're asking for?

Depth Time
24 1
21 1
18 1
15 1
12 1
9 2
6 3
3 5

 

[Mike Edmonston]

This is my point - what is safe? A lot of people have criticised me for using 1.7x PPO2, and I accept that, it's dangerous, no doubt. But then the same people suggested using 'safer' mixes that are also conventionally considered 'unsafe' but to "lesser" degrees?

I will post some runtimes for you when I get back to the shop. BTW, just to be clear, the narcotic mix that I suggested was not hypoxic, nor was it unsafe to breathe at 1ATA (sea level)

Just a thought though, you guys had a bottle of o2 at 20', therefore 15% would not be a hypoxic issue because you would switch to this bottle if the instructor was air sharing with you.

Cheers

 

[Tortuga68]

Just a thought though, you guys had a bottle of o2 at 20', therefore 15% would not be a hypoxic issue because you would switch to this bottle if the instructor was air sharing with you

True, although the original plan was to ascend from the last deco stop on back gas

 

[Tortuga68]

All VPM-B +2

Thanks for posting the runtimes, looks like they are pretty similar between the two bottom gasses, that's good. They're actually shorter than the decoplanner times, which started with 1@27m I think and went on sequential 1s up to 15, then 2@12, 3@9 and 12@4.5 (from memory, my logs etc are still in the PI) plus 3 minutes to the surface for a total dive time of around 40 minutes

However, although they're close, your trimix runtime would have my instructor/buddy above me for part of the deco, which is a no-no in PSAI terms. One of the 'rules' is that I should never be deeper at any time during the dive

 

[LiteHedded]

True, although the original plan was to ascend from the last deco stop on back gas

weird...

 

[ucfdiver]

Thanks for posting the runtimes, looks like they are pretty similar between the two bottom gasses, that's good. They're actually shorter than the decoplanner times, which started with 1@27m I think and went on sequential 1s up to 15, then 2@12, 3@9 and 12@4.5 (from memory, my logs etc are still in the PI) plus 3 minutes to the surface for a total dive time of around 40 minutes

However, although they're close, your trimix runtime would have my instructor/buddy above me for part of the deco, which is a no-no in PSAI terms

I used decoplanner to cut those tables, decoplanner supports vpm and Buhl with GF.

What gradient factors did you guys use?

 

[Tortuga68]

weird...

Why so? Deco is complete