Dir, utd, wtf?

[netmage]

FWIW I've never dove with a UTD diver. I've dove with several GUE divers, so rather than talking out of my a$$ I can only say what my c2 buddies would do. The above schedule posted in the UTD classroom might not represent what other UTD instructors or divers would do. I hope rjack comments here.

I wouldn't call it an extreme example - I'd call it a normal dive at Ginnie...

On this note, I've heard rumors that GUE will take away certifications from a diver for certain offenses. I do not know if UTD will do likewise. Is this true? If so can anyone provide an example of an offense of "de-certifying" magnitude.

For instructors or divers....? You see; the beauty of the expiring c-cards paradigm, if you fall away from the philosophy, go against the grain, or are found to perform in an unsafe manner; they don't have to revoke your card, they can simply choose to not reissue a new one upon expiration... A vastly different mechanism...

 

[rjack321]

The eternal fate of your soul is not riding on this.

Unless you're privy to something we're not maybe it does...:blinking:

Seriously I don't see the point of another "how deep is too deep" air thread AGAIN. Too deep is somewhere between your head wet and passing out from narcosis.

I do find it interesting that TDI, one of the largest AN/DP programs in the world now allows trimix instructors to teach AN/DP with light trimix instead of just air for the ~160ft dives. Apparently various instructors in colder darker waters like BC and the UK were requesting changes in the standards. Allowing them to include some trimix at the entry deco level and keep the ENDs more in line with what is encouraged in later deeper trimix classes (~100ft).

 

[Slamfire]

For instructors or divers....? You see; the beauty of the expiring c-cards paradigm, if you fall away from the philosophy, go against the grain, or are found to perform in an unsafe manner; they don't have to revoke your card, they can simply choose to not reissue a new one upon expiration... A vastly different mechanism...

I was asking about divers, not instructors. I would not be too surprised if instructor c-cards expire, but are you saying that diver cards also expire? If they do, do you at least get a more or less automatic renewal?

I do find it interesting that TDI, one of the largest AN/DP programs in the world now allows trimix instructors to teach AN/DP with light trimix instead of just air for the ~160ft dives. Apparently various instructors in colder darker waters like BC and the UK were requesting changes in the standards. Allowing them to include some trimix at the entry deco level and keep the ENDs more in line with what is encouraged in later deeper trimix classes (~100ft).

I guess this came in too late for me. It was all air for me during the training. Is it only instructors using He or are the students also allowed to use He? The max depth for AN/DP is 150' on air. The extended range course goes to 180' on air. Are they now expanding AN/DP to 160' if helium is used?

 

[rjack321]

Re: the 120min @ 70ft ratio deco example. Sorry missed this earlier.

AH was close in his answer but I think he missed a big issue. There are now 2 ways of coming up with an RD profile for 02 deco dives.
Approach#1 is the 1:1 method for 25/25 dives in the 100-130ft range.
Approach#2 is the "time over" approach for shallower (e.g. 32%) dives.

He mixed these up a bit by putting 1/2 the deco time up to 20ft and 1/2 the time above which is not the right way to deal with "time over" plans, its just the newer 1:1 plan way - which only applies deeper (I really wish AG hadn't gone this route for the 25/25 dives with O2 although it is drop dead simple for a 120ft dive it doesn't apply shallower and for 32% where you still have to do "time over").

Time over MDL approach:
MDL for 70ft on 32% is 50mins
70mins over

Shape backgas exponential (Fibonacci if you really want, this is the cheater way)
70mins needed total 70/2 = 35mins
35mins left 35/2 = 17mins
18mins left 18/2 = 9 mins
9mins left 9/2 = 5 mins
4mins left 4/2 = 2 mins, 2mins left can put this anywhere I'll just split it between this stop and the next

Backgas deco =
10ft: 35min
20ft: 17
30: 9
40: 5
50: 3
60: 1

Add time credit for O2
35 + 17 = 52mins of shallow time 52/2 for O2 credit = 26 mins

Final schedule
10: 5mins up on O2
20: 21mins O2
30: 9
40: 5
50: 3
60: 1

Obviously the old MDL table which UTD is still using is very conservative with 32% in the mid-depth range (50-70ft). Much more conservative than GUE's fancy new NOAA table. I really have no idea what decoplanner or VPM would advise for this dive, maybe someone else can compare, its a bit outside my personal experience.

 

[rjack321]

I guess this came in too late for me. It was all air for me during the training. Is it only instructors using He or are the students also allowed to use He? The max depth for AN/DP is 150' on air. The extended range course goes to 180' on air. Are they now expanding AN/DP to 160' if helium is used?

Its students and instructor. But I don't actually know the details, talk to Doppler and/or wedivebc. They discussed it somewhere but I don't know the posts or even the board its discussed on. Just something I saw in passing, if I remembered where I'd post a link

 

[Rainer]

I really have no idea what decoplanner or VPM would advise for this dive, maybe someone else can compare, its a bit outside my personal experience.

I'm not firing up the PC to check DP, but V-Planner (VPM-B, +2 conservatism) gives (for 120 minutes at 70' on 32% with O2 for deco): 8 minutes at 10'.

Even "time over" gets really conservative for these longer, shallow dives.

Edit: Blackwood and I are planning a similar dive to this for next month (2 hrs at 80' average; "time over" is just needless extra deco; as mentioned, there are points at which you're better consulting software than trying to extend RD profiles beyond their intended operational window).

 

[ucfdiver]

Richard, thanks for commenting.

VPM-B+2 requires 10min @ 20ft.

Buhl 20/85 GF requires 1min @ 30ft and 11min @ 20ft

Almost triple the deco seems a bit steep for me, but I do understand that these methods aren't designed to exactly mirror each other. Seems to me that the answer I received from an instructor wasn't a good one. It's like asking how to dive a SM cave DIR and getting told to bring a shovel...sometimes the answer is this system wasn't designed for the dive. I'm OK with that, and will modify my diving as needed, but I don't like an answer that comes out of well....you know where ;-)

 

[rjack321]

For instructors or divers....? You see; the beauty of the expiring c-cards paradigm, if you fall away from the philosophy, go against the grain, or are found to perform in an unsafe manner; they don't have to revoke your card, they can simply choose to not reissue a new one upon expiration... A vastly different mechanism...

T, have you kept your GUE card(s?) current/active?

 

[netmage]

I was asking about divers, not instructors. I would not be too surprised if instructor c-cards expire, but are you saying that diver cards also expire? If they do, do you at least get a more or less automatic renewal?

I guess this came in too late for me. It was all air for me during the training. Is it only instructors using He or are the students also allowed to use He? The max depth for AN/DP is 150' on air. The extended range course goes to 180' on air. Are they now expanding AN/DP to 160' if helium is used?

Automatic - no... You have to demonstrate a minimum amount of activity at your highest training level, I wold also assume for both cave and deco if applicable. I believe the requirement is 25 dives over the three year period - but I could be wrong. The point is that if you hang up your fins for an extended period of time, you are no longer qualified to perform at those levels. And the philosophy requires you to "do the right thing" and prepare yourself mentally and physically to perform the dives safely. It's my understanding you simply have to submit your log book to your instructor and pay the admin fee.

 

[ucfdiver]

T, have you kept your GUE card(s?) current/active?

I'm aware of GUE C2 divers who solo dive and use a meg and have renewed without issue. In this economy, I doubt GUE is dying to turn down renewal fees.