My AN/DP/Helitrox course

[lowviz]

I think there is about a 60% overlap between AN and DP really. So doing both at the same time is the sensible plan.

Then there really should be no AN course. Get rid of it?

I disagree. Everything overlaps to some degree. I would hazard to say that most divers simply fly their computers.

Why they allow AN on its own I do not know, maybe there are use cases but if you cannot do deco what are they? A multi level dive with air on the bottom and 50% shallow? Really? Using O2 at 6m for three minutes? Sure...

I'll take pure O2 on any dive but it will be slung on the right. Right is Rich. For me, pony on the left. Never any reason to touch the solo pony, but it gets out a lot. If one is diving pure O2 then the secondary on that cylinder should be made distinct. Some cover it with a fabric hood, others make it impossible to accidentally mistake it for a stage bottle by other means.

I often dive a pony (on the left) and O2 (on the right) solo. Since I have it, I'll do an over-long safety stop on O2. Makes me feel better. Never touch the pony. Just purge and shut off on every dive. Funny how fast the gas in a 19 disappears by just purging it...

This use of pure O2 (per AN teaching/requirements) is all about self-discipline. And THAT is a really good intro to 'Intro to Deco Procedures'.

...//... Even if you don’t do long deco dives, knowing how and applying those techniques to whatever dives you are doing will improve your safety.

Indeed.

...//... The TDI manuals are not brilliant. Diving manuals in general are quite non specific about how skills should be done.

They ALL need a serious re-write...

 

[rddvet]

. If one is diving pure O2 then the secondary on that cylinder should be made distinct. Some cover it with a fabric hood, others make it impossible to accidentally mistake it for a stage bottle by other means.
...

with the appropriate gas switch procedure of identifying the bottle by markings and tracing the reg hose back to the bottle there is no reason to distinctly mark the reg. In fact.many good instructors teach not to use a reg distinction because it leads to the complacency of not actual tracing the reg back to the bottle.

 

[Mike1967]

there is no reason to distinctly mark the reg.

Doesn't just the fact that it's green make it distinct? As long as all your regs aren't green of course.

 

[KenGordon]

Then there really should be no AN course. Get rid of it?

I disagree. Everything overlaps to some degree. I would hazard to say that most divers simply fly their computers.

I'll take pure O2 on any dive but it will be slung on the right. Right is Rich. For me, pony on the left. Never any reason to touch the solo pony, but it gets out a lot. If one is diving pure O2 then the secondary on that cylinder should be made distinct. Some cover it with a fabric hood, others make it impossible to accidentally mistake for a stage bottle by other means. I often dive a pony (on the left) and O2 (on the right) solo. Since I have it, I'll do an over-long safety stop on O2. Makes me feel better. Never touch the pony. Just purge and shut off on every dive. Funny how fast the gas in a 19 disappears by just purging it...

This use of pure O2 all about self-discipline. And THAT is a good intro to 'Intro to Deco Procedures'.

Indeed.

They ALL need a serious re-write...

What are these dives that make you think you need 100% but are not deco dives?

 

[RayfromTX]

color causes problems. It's fine for convenience but not for actual use protocol under water. Sometimes regs fail and are switched out just before a dive. Color shouldn't play into which reg you stick in your mouth. Trace the hose from the tank to the reg.

 

[rddvet]

Doesn't just the fact that it's green make it distinct? As long as all your regs aren't green of course.

there are a lot of people who don’t use green regs for oxygen

 

[RayfromTX]

I use green regs for 50% and for 100% because they were cheap. I get a ration of crap from people that would never rely on color to determine the mix from a reg but think green for 50% is dangerous. I have had someone say they would refuse to dive with me because of it but we would never have dived together anyway. There is lots of self righteousness in the world of technical diving. I just try to take it in stride as I learn and try to avoid arrogance in my own understanding of things. I'm always learning and started too old to ever get where I'd like to be.

 

[rddvet]

I use green regs for 50% and for 100% because they were cheap. I get a ration of crap from people that would never rely on color to determine the mix from a reg but think green for 50% is dangerous. I have had someone say they would refuse to dive with me because of it but we would never have dived together anyway. There is lots of self righteousness in the world of technical diving. I just try to take it in stride as I learn and try to avoid arrogance in my own understanding of things. I'm always learning and started too old to ever get where I'd like to be.

I agree thats very stupid. I have no issue with colored regs even for 50%. My 100% regs have a green faceplate and hose. My only issue is people who are trained to rely on the color to identify the reg. Its dangerous. But if you are using the color to initially locate the reg but are then still tracing it back to the bottle I have no issues. The problem is alot of people are taught identifying color is good enough.

 

[Graeme Fraser]

I agree thats very stupid. I have no issue with colored regs even for 50%. My 100% regs have a green faceplate and hose. My only issue is people who are trained to rely on the color to identify the reg. Its dangerous. But if you are using the color to initially locate the reg but are then still tracing it back to the bottle I have no issues. The problem is alot of people are taught identifying color is good enough.

I'd be surprised if anyone was actually taught it was OK to just identify by colour. However, I would agree that some people lax into dreaded old complacency.

Certainly all the tech agency curriculums, training manuals and instructor guides I've read are very explicit about the correct procedure for gas switches, including a deliberate tracing from 2nd to 1st stage and cylinder.

Like many things, people get away with it... untill they don't!

 

[Graeme Fraser]

I'd be surprised if anyone was actually taught it was OK to just identify by colour. However, I would agree that some people lax into dreaded old complacency.

Certainly all the tech agency curriculums, training manuals and instructor guides I've read are very explicit about the correct procedure for gas switches, including a deliberate tracing from 2nd to 1st stage and cylinder.

Like many things, people get away with it... untill they don't!

I should add that I don't see anything wrong at all with colour coding and / or labelling regs, but as additional identification, not the only check. Indeed, my stage reg faceplates are all green (although it doesn't necessarily help much being colour blind).