My AN/DP/Helitrox course

[MichaelMc]

I admit to some confusion here and I do know I had a very good instructor but you simply can not judge a course by the manual alone.

Are you saying the course does not have you dive a deco tank? Not hold a stop while switching over to the deco tank? Not rigging said tank? Not knowing how this will affect your dive plan?

(Sorry Marie13 if this is hijacking your thread)

This is TDI's entire description of the in-water skills to be conducted:
https://www.tdisdi.com/wp-content/uploads/files/sandp/currentYear/TDI/part 2/pdf/individual/TDI Diver Standards_07_Advanced_Nitrox_Diver.pdf

• Demonstrate buoyancy control; ability to hover at fixed position in water column without moving hands or feet
• Show good awareness of buddy and other team members through communication, proximity, and team oriented dive practices
• Demonstrate the ability to manage free flow from primary regulator in controlled fashion, shut down cycle, and switch to back up regulator
• Conduct appropriate safety stop while maintaining neutral buoyancy
• Demonstrate the ability to share air with buddy as both recipient and donor in a controlled manner while maintaining position in the water column
• Demonstrate correct body position; appropriate trim, such as horizontal/streamlined when moving forward
• Demonstrate proper stress analysis with self and dive buddy

That is very much basic diver or intro tech. The on land has bits about analyzing tanks and O2 exposure. Take a look through both. The pdf is the more in depth.

As reason for the class, the fourth sentence of the manual's intro is:
"A diver may simply want to have the option to use oxygen for his safety stops during recreational sport dives." The fifth sentence is they may then go on to DP, Trimix, CCR.
In protocols:
"During the course, gas switches may be conducted." p75.

But nothing about
- marking tanks beyond tanks should be labeled. Which is true for EAN32 tanks. Not anything about big OXYGEN or MOD labels.
- how to rig, carry or stitch to other gas mixes.

That is the knowledge, skill list, and manual that TDI publishes.

That is not the TDI instructor manual. But TDI seems to publish the skills expected of the class, though maybe not the measure of the skill. What is good awareness? Appropriate safety stop?

They allow instructors to do more. That more is not the class that TDI publishes. So I would judge the TDI class by what TDI publishes.

I would judge a shop or instructor say the UnderTheJungle class by what UnderTheJungle publishes.

 

[MichaelMc]

Some skills from the TDI DP list:
https://www.tdisdi.com/wp-content/uploads/files/sandp/currentYear/TDI/part 2/pdf/individual/TDI Diver Standards_08_Decompression_Procedures_Diver.pdf

# Demonstrate ability to drop and retrieve single decompression cylinder while maintaining position in the water column
# Demonstrate ability to confirm gas switch(es) at depth with buddy/team members
# Demonstrate the proper deployment, management and use of the bottom mix, decompression mix and travel mix, if used, including but not limited to:
- a. Conservative gas management
- b. Depth control to avoid descending too deep for mix
- c. Show appropriate and timely responses to instruction / signals from the instructor and demonstrate buoyancy control and awareness throughout the dive

To make it clearer, replace deco above with 'rich mix or O2 used shallow'.
Those seem applicable to carrying multiple gases for non-required staged deco dives. They are not on the AN skills list.

 

[MichaelMc]

AN multi gas dive planning for O2 is limited to that you count O2 limits by the minute. So you can do it for the different mixes and depths.

In the dive planning chapter, the AN multi gas planning for N2 exposure seems limited to this:
"Dive profile planning should be conducted before each dive via dive computer, computer based software or dive table. Breathing gas choices should be made to optimize breathing mixtures to extend no stop bottom times within each dive."
Then a short paragraph saying tables are traditional, can be used via EAD but are limited by assuming max depth. Instructor to review tables if they are to be used.

Most of that dive planning chapter in taken up by the four pages of basic SAC calculation in imperial and metric.

Thats it.
ETA: A appendix talks about Buhlmann tables for deco dives but not multi gas dives. Three pages of text, three pages of table.

 

[uncfnp]

Ok. I see your points and all I have to go by is my experience taking it as a stand alone class and its usefulness to me. Certainly not pertinent to the current discussion.

 

[MichaelMc]

I think AN is good for expanding no deco dive options or getting surface O2. (Though DAN O2 admin issues a card for surface O2 fills.)

AN seems best if the instructor covers a few things from TDI DP that look like they should be in TDI AN for better safety. And a better manual would be nice.

Sorry for the tangent Marie13.

 

[Marie13]

Eh, it was an interesting tangent.

 

[Jack Hammer]

@MichaelMc I found my TDI AN course useful. It gave me a much better understanding of the pros and cons of O2 and the importance of properly maintained equipment for O2 usage. I think it goes well with DP and wasnt a waste of time at all. Based on how dissatisfied you seem with the course, perhaps you should ask your instructor for a refund.

 

[MichaelMc]

@MichaelMc I found my TDI AN course useful. It gave me a much better understanding of the pros and cons of O2 and the importance of properly maintained equipment for O2 usage. I think it goes well with DP and wasnt a waste of time at all. Based on how dissatisfied you seem with the course, perhaps you should ask your instructor for a refund.

I have not taken the class. I have the manual and TDI's description in preparation for taking the class somewhere. I am disappointed in the manual, which is required material for the class. So returning the manual would be counter productive, no matter what I feel about the manual.

TDI publishes class content with required student performance, and certs instructors on it. They also may allow additional content. I am happy TDI allows additional content. I am disappointed with their provided and required content for this class. Their provided and required content for AN seem like Intro to tech plus nitrox/O2 math. That seems short for letting me strap O2 and 50% on my body and go diving.

In the dive class market I like TDI AN/DP. Just AN by itself seems to have some required skills shortcomings. That totally give me freedom to not learn them if my instructor does not add them. I just think that is not the best way for the class to be defined by TDI.

Unless there is a secret addendum in the instructor manual that says:
"If AN is taken by rebreather divers for O2 access, the standards are as published, as they will be on the loop or learn bailout safety in their rebreather class. If taken alone by non-rebreather divers, add 'how to avoid breathing a deadly gas underwater' from DP and all the depth and gas switch stuff to go with that."

 

[RainPilot]

True, but it is perfect for some...

I like that options exist, even if they are not applicable to every (or even most) student/s. AN making "more sense" to most users in combination with DP leads to most instructors offering (and most students taking) the courses combined. I certainly would not recommend someone taking AN alone if their intention was to progress to. trimix later. However I can certainly see the utility of AN for certain use cases, and why not?

NAUI certainly has some courses (some I am even qualified to teach) that leave me perplexed as to why ANYBODY would ever need that, but no skin off my nose, someone somewhere needed it and there it is.

 

[KenGordon]

I have not taken the class. I have the manual and TDI's description in preparation for taking the class somewhere. I am disappointed in the manual, which is required material for the class. So returning the manual would be counter productive, no matter what I feel about the manual.

TDI publishes class content with required student performance, and certs instructors on it. They also may allow additional content. I am happy TDI allows additional content. I am disappointed with their provided and required content for this class. Their provided and required content for AN seem like Intro to tech plus nitrox/O2 math. That seems short for letting me strap O2 and 50% on my body and go diving.

In the dive class market I like TDI AN/DP. Just AN by itself seems to have some required skills shortcomings. That totally give me freedom to not learn them if my instructor does not add them. I just think that is not the best way for the class to be defined by TDI.

Unless there is a secret addendum in the instructor manual that says:
"If AN is taken by rebreather divers for O2 access, the standards are as published, as they will be on the loop or learn bailout safety in their rebreather class. If taken alone by non-rebreather divers, add 'how to avoid breathing a deadly gas underwater' from DP and all the depth and gas switch stuff to go with that."

I think there is about a 60% overlap between AN and DP really. So doing both at the same time is the sensible plan. 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 suggest you do both. ANDP is a good course and will give you a proper understanding of the processes and skills needed to do these dives properly. 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.

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