Agencies?

[rjack321]

Meh, I've known (and know) excellent instructors with both agencies. And some who couldn't teach or dive their way out a paper sack. Who's the OP taking a course from anyway?

---------- Post Merged on September 18th, 2012 at 09:23 AM ---------- Previous Post was on September 17th, 2012 at 04:20 PM ----------

Assuming the OP comes back, here's my slightly tongue in cheek advice...

1. If you have no "DIR" buddies you are hosed. Go find someone to take a class with you.

2. If you have some GUE buddies already you have 2 choices:
a. Take GUE training and get called a lemming along with your buddies
b. Go all contrarian and take UTD training. Discover all the silly GUE-isms like 30/30 and decoplanner with gradient factors after class (vintage!).

3. If you have some UTD buddies already you also have 2 choices:
a. Take UTD training, and potentially get exposed to a bunch of crazy BS ideas which will never be "DIR" like sidemount "manifolds" and mixed CCR-Open circuit teams.
b. Take GUE training and piss off your buddies by being a cliche of 1.

If you haven't figured it out yet, I would find an instructor who's as local to you as possible and who is diving the way you want to. Take a class from them unless he(she) is a total jerk. If that's the case, go back to step 1.

 

[rlynch]

Not marking your deco bottles is crazy... Do they use colored regulators too?
Green for O2, pink for whatever

 

[Blackwood]

Not marking your deco bottles is crazy... Do they use colored regulators too?
Green for O2, pink for whatever

They teach to mark deco bottles with MOD labels, but not stage bottles. And all bottles have content labels.

 

[rlynch]

well that's good but implies that UTD only marks the 50/50 and 100% bottles (if that is the std deco gas for UTD, dunno) - why wouldn't you make your stages? switching to a 120' bottle of travel gas at say 330 fsw is just as deadly (that is example is from a real dive my friends (Non-DIR btw) did on the sms osfriesland. masking tape comes off easy underwater so the contents labels are not good enough, IMHO. I do not have any understanding of UTD so its actually a serious question.

 

[Rainer]

(1) Most dive 50%, not 50/50.

(2) There are a lot more than two standard deco gasses.

(3) There really aren't "travel gasses" for "DIR" dives. Just use a deco bottle.

(4) Don't use masking tape for your contents label. Ultimately, the contents label is more important than the MOD label. Only the former has your initials and date, confirming *you* actually analyzed the gas in that cylinder. [That said, the MOD label is crucial for a teammate verification.]

(5) Not marking stage bottles IS dumb. All the UTD trained divers I know (minus UTD instructors) mark their stages with MOD stickers.

well that's good but implies that UTD only marks the 50/50 and 100% bottles (if that is the std deco gas for UTD, dunno) - why wouldn't you make your stages? switching to a 120' bottle of travel gas at say 330 fsw is just as deadly (that is example is from a real dive my friends (Non-DIR btw) did on the sms osfriesland. masking tape comes off easy underwater so the contents labels are not good enough, IMHO. I do not have any understanding of UTD so its actually a serious question.

 

[Blackwood]

well that's good but implies that UTD only marks the 50/50 and 100% bottles (if that is the std deco gas for UTD, dunno) - why wouldn't you make your stages? switching to a 120' bottle of travel gas at say 330 fsw is just as deadly (that is example is from a real dive my friends (Non-DIR btw) did on the sms osfriesland. masking tape comes off easy underwater so the contents labels are not good enough, IMHO. I do not have any understanding of UTD so its actually a serious question.

UTD standard deco gases are: 100%, 50%, 35/25, and 21/35, and are the bottles are marked as "20 OXYGEN", "70", "120" and "190" respectively (imperial units).

In the UTD Lexicon, an unmarked "stage bottle" contains bottom mix - it's breathable as deep as you're going to go.

As to why they don't mark it, I don't remember the exact discussion, but it had something to do with overlapping gases within a depth range. Say I'm doing two dives on the oil rigs. One dive is planned to 300+. For the 300+ dive, I have a switch to 21/35 at PO2=1.4, and that deco bottle is marked "190." Another dive is planned for 190, for which I have 18/45 in a stage. My bottom MOD for that dive is 1.2, so the stage bottle is marked "190." Two bottles, same MOD marking, different gases.

In both cases, you have to look at the content label to know what's in it, and UTD feels there's value in a visual indication (i.e. no MOD label) that a bottle contains bottom mix. If I were diving with a AG on the 190 dive and I saw him on a 190 bottle at 190, I'd tell him to switch off because it should contain 21/35 as marked (as opposed to 18/45 as planned).

Something like that. Personally, I mark all my bottles with MOD, stage and deco, and I rely primarily on the contents label, as should all divers IMO (and I suspect both GUE and UTD brass agree with those sentiments).

 

[rlynch]

Thanks for clarifying - I meant 50% o2, not 50% O2, 50% He when I said 50/50. my mistake.

 

[PfcAJ]

GUE Deco gases are 20,70,120,190, 240
Bottom gases are 100,150,200,250,300

No ambiguity there.

And who does a 300ft dive then a 200ft dive back to back?

Fwiw, I rely on the MOD sticker at depth. the entire point of a mod sticker is so you aren't doing math underwater (33.4%, so thats for 120, right?). Do the maths on the surface. In my view, a bottle doesnt leave the shop without being analyzed, and a bottle doesnt get a reg unless the MOD and the analysis jive with each other. This is all done on the surface, before you get on a boat, or in the water in a cave.

 

[Blackwood]

GUE Deco gases are 20,70,120,190, 240
Bottom gases are 100,150,200,250,300

No ambiguity there.

Word. I like that better, but you know... different strokes for different folks.

And who does a 300ft dive then a 200ft dive back to back?

People who aren't doing 90 minutes at depth. Not I, however - 300 is far deeper than I'm qualified for.

Fwiw, I rely on the MOD sticker at depth. the entire point of a mod sticker is so you aren't doing math underwater (33.4%, so thats for 120, right?).

What math? I know what gas I need to be using at my switch. When I hit 70 feet, I don't go "okay, okay... 1.6... 1.6/(1+70/33)=.51, and I have one that says 50%, sweet." I go "I'm supposed to be going to 50% - that's what the contents label says, sweet." Then I show my buddy the "70" and get confirmation that the bottle I think I grabbed is the bottle I actually grabbed. NDB.

Do the maths on the surface. In my view, a bottle doesnt leave the shop without being analyzed, and a bottle doesnt get a reg unless the MOD and the analysis jive with each other. This is all done on the surface, before you get on a boat, or in the water in a cave.

Yep.

 

[PfcAJ]

Meh, I don't really care. We do it differently. Look at a sticker (I prefer MOD, you prefer analysis, w/e), and have your buddy check it. Fair nuff.

But they've got to be marked, even stages. Not looking at stages is a sore subject for me.