Trimix 1 Class

[chickdiver]

Mike,

I agree with you (mostly). I think the arbitrary depth and/or mix limitations are a crock. If you understand the math for trimix at 190' then you understand the math for trimix at 290', etc.; the same thing applies with procedures and decompression. However, mental preparation is a lot tougher for the deeper dives (over 250' in my opinion), and you also have to be dead on with the skills and the contingency plans, because there isn't as much time when things start to go wrong. I think that for the deeper dives expereince is the key. I don't think that most dives conducted in a "training" guise are very good for building that kind of expereince. To gain that expereince you have to be out there doing progressively more challenging dives with a group of people who know thier stuff- int hat case I think mentoring is really the key.

 

[MechDiver]

MikeFerrara once bubbled...


Actually the way the IANTD standards read no more than 30% He can be used in the class (don't ask me why).

True, but I have seen nothing that says once you are out of the class that you are still "limited" to 30% He. Would make no sense anyway. As you have a shop, do you limit mix fills to 30% for anyone holding a normoxic card?

MD

 

[O-ring]

MechDiver once bubbled...


True, but I have seen nothing that says once you are out of the class that you are still "limited" to 30% He. Would make no sense anyway. As you have a shop, do you limit mix fills to 30% for anyone holding a normoxic card?

MD

I would be curious what your procedures (and others' procedures) are for people holding depth limited cards. For example, will you not sell a customer a mix that is intended for use deeper than a customer's card permits? (i.e. would you sell a Tech 1 cardholder 18/45?).

 

[MechDiver]

O-ring once bubbled...

I would be curious what your procedures (and others' procedures) are for people holding depth limited cards. For example, will you not sell a customer a mix that is intended for use deeper than a customer's card permits? (i.e. would you sell a Tech 1 cardholder 18/45?).

What is the depth limit for Tech 1? Is that the 165' that Pug mentioned?

 

[O-ring]

MechDiver once bubbled...


What is the depth limit for Tech 1? Is that the 165' that Pug mentioned?

..at least that's what the site says...I thought it was 130'.

 

[MechDiver]

O-ring once bubbled...

..at least that's what the site says...I thought it was 130'.

Concerning your other question, I called a shop in Seattle and could get 18/45 using my IANTD card. Technically that is within my training guidelines, although the 18% is fugded a little. I was concentrating on the He content and did not directly ask about a hypoxic mix. He said they sell alot of 16/60 and mix what is asked for.

MD

 

[MikeFerrara]

chickdiver once bubbled...
Mike,

I agree with you (mostly). I think the arbitrary depth and/or mix limitations are a crock. If you understand the math for trimix at 190' then you understand the math for trimix at 290', etc.; the same thing applies with procedures and decompression. However, mental preparation is a lot tougher for the deeper dives (over 250' in my opinion), and you also have to be dead on with the skills and the contingency plans, because there isn't as much time when things start to go wrong. I think that for the deeper dives expereince is the key. I don't think that most dives conducted in a "training" guise are very good for building that kind of expereince. To gain that expereince you have to be out there doing progressively more challenging dives with a group of people who know thier stuff- int hat case I think mentoring is really the key.

No argument here. Thats why I say that too me the limiting factor is depth/time not gas. As far as I'm concerned depth/time increases risk and makes precision more critical. I also agree that depth and time should be increased gradually. It's better to make little mistakes on short shallow dives than on long deep ones making a little mistake a big one.

 

[MikeFerrara]

MechDiver once bubbled...


As you have a shop, do you limit mix fills to 30% for anyone holding a normoxic card?

MD

Not that I have a line of divers witing for trimix fills (I am by far my best customer) but I guess I'll do what makes sense to me at the time. I know that isn't much of an answer but that's the best I can do. On another note all the mix divers I know mix it themselves.

 

[MikeFerrara]

O-ring once bubbled...

I would be curious what your procedures (and others' procedures) are for people holding depth limited cards. For example, will you not sell a customer a mix that is intended for use deeper than a customer's card permits? (i.e. would you sell a Tech 1 cardholder 18/45?).

See my post above. I don't know what the limits of a tech 1 are. Within reason I certainly wouldn't want to tell someone what gas they should use for a dive. It's a little obviouse that a card that says "normoxic" on it wasn't intended as a ticket to get 10/70. On the other hand if a guy wants 18/? to keep his PPO2 down on a long dive should...? I have to baby-sit OW divers I'm not going to get in the habbit of watchinh technical divers. Within reason I'll do what makes sense.

 

[ericfine50]

O-Ring,

I think GUE is still playing with the Tech 1 depth limit. Tri-Ox is rated to 120, so I am not sure if they are going to stay with the 150 or move it to 165? Do you think people will want to take a Tech 1 that is rated to 150? Don't know, just throwing out questions.
Eric