Rate This Series of Dives...

[Shcubasteve]

Dive one: 185' for 20 minutes on air with 70% deco, RT= 60 minutes
SI: 1 hour
Dive two: 100' on 35% for 25 (within NDL)
SI: 45 minutes
Dive three: 90' on 36% for 35 (within NDL.)

Totally hypothetical scenario
Would you consider this series of dives to be:

• Conservative
• Moderate
• Aggressive

In other words, would you make this series of dives? Why or why not?
Please rate the profiles first and if need be, the use of air past 165' second
Thanks Steve

 

[PfcAJ]

Aggressive. I wouldn't dive to 185 with only 1 gas, it certainly wouldn't be 70%, and it sure as hell wouldn't be on air. Dives 2 and 3 wouldn't happen because dive 1 wouldn't have left the drawing board.

 

[anytime]

Aggresive. Unless there was something really important and interesting to see on the first dive I might cut the bottom time back to 15mins, but I would dive it either way. On the other dives, my computer would not give me as much bottom time. I might be able ot go for 20 mins on the second and about the same on the third before I went into deco again.

 

[MikeMarlow]

Aggressive, since the 3rd dive is pushing the CNS over 100%...not something I want to mess with. 185 on air is within the MOD, and we all regularly push other mixes to near the MOD, yet for some reason going there with air is "crazy." Are there better gasses, sure, but you need to take another class to get the really wacky gas, which would make this a moderate to conservative dive.

Mike

 

[wmperry]

I am TriMix certified so I would not do dive 1 on air... 21/20 if not more. I've never felt narced until my T165' training dive on air. Was bearable but really needed to focus or my mind started wandering. Did NOT like that feeling underwater and doing the same dive profile the next day on 21/20 is what sold me on taking TriMix.

I would rate it aggressive because of narcosis concerns, not pushing the MOD. I won't play deep air police, but I wouldn't do it.

 

[LiteHedded]

my suggestion is to just slap all those dives together. something like this:

 

[ucfdiver]

Aggressive, since the 3rd dive is pushing the CNS over 100%...not something I want to mess with.

Why not?

 

[PfcAJ]

CNS "%" values are highly suspect, given that you can tox well below 100%, and 100% doesn't mean you will tox (I'd be long gone if that were the case). That said, repetitive dives that expose you to a high ppo2 are probably ill advised.

 

[Doppler]

Suggested dives exceed NOAA 24-hour limit and therefore I'd suggest categorizing 'em as ill-advised... notwithstanding possible other issues.

 

[amascuba]

agressive.

Dive one looks agressive deco wise for the run time and gas choices. Doing the same dive with helium in the backgas and two deco gases would give me a similar run time. I'd expect more deco with air as a backgas and the single deco gas. Probably closer to 80 minute run time.

it doesn't need to be said, but doing the dive on air isn't the most brilliant move in the world.

I'd want a longer Si between the dives. Atleast 90 - 120 minutes.

I'd also want a lower O2 content on dives two and three because the lungs are already going to take a beaten from the first dive.