Nitrox class - no dives/dives?

[NAM001]

My nitrox dive in 2003 required dives and changing from one mix to another in your computer. Perhaps 4 ears ago my wife took nitrox and it was all classroom and all that was really required was watch a dvd take a test (just like online) and then demonstrate salmpling 2 tanks. If you brought a computer you had to adjust the mix. If you did not bring a computer then you just had to know to change the mix.
I can not imagine any water skills related to nitrox.

 

[Bigbella]

My course, back in the nineties, was through NAUI, and required a few dives, by the tables, and a ridiculously simple written test.

For recreational diving, one shouldn't exceed the folllowing PO2?

A. 1.4
B. Suspension bridge
C. San Marzano tomato
D. All of the above

 

[boulderjohn]

My nitrox dive in 2003 required dives and changing from one mix to another in your computer.

Switching from one mix to another during a dive? In a recreational nitrox class? That is a technical diving skill.

Switching gases in the computer on the surface, on the other hand, is just another way of saying "setting your computer to the correct mix for the dive."

Which was it?

 

[NAM001]

Switching from one mix to another during a dive? In a recreational nitrox class? That is a technical diving skill.

Switching gases in the computer on the surface, on the other hand, is just another way of saying "setting your computer to the correct mix for the dive."

Which was it?

setting the computer on the surface for the gas you wlll be using prior to getting in the water. I had to per nauii use 2 different nitrox mixes .... dive one then get out change tanks to another mix and change gas mix on the computer, then dive that tank.

 

[OceanEyes]

I took the IAND class in July of 1991 with Dick Rutkowski, the man who literally wrote the book on civilian Nitrox diving following his retirement from NOAA. The classroom session lasted about 4 hours, covered all the necessary bases regarding math, physics, tables, and physiology, and was followed by analysis of an array of cylinders. I do not believe that dives were required, (Dick certainly did not dive that day), but most of my class joined an afternoon 2 tank trip offered by the neighboring dive shop, Ocean Divers.

I don’t think that Nitrox computers were readily available at that time, (I was using an Aladdin Pro in those days), so programming one was not part of the course. My son earned his TDI/SDI Computer Nitrox certification about 10 years ago, and setting the O2 content on a computer was an integral part of his course. I do not recall all the details precisely, but I do not believe that dives were required for his course.

 

[Mike1967]

Hey guys,

Quick question to make sure I'm thinking straight.
If I was diving twin SM with one tank at 21% and one at 33%, I'd set my computer at 27%?

Cheers, Mike

And of course not go deeper than the MOD for 33%

 

[Jcp2]

Are you alternating regulators between breaths?

 

[Mike1967]

Are you alternating regulators between breaths?

No but tanks will start with the same pressure and end the same. Breathing the first tank down 10 bar then alternating 20 bar each.

 

[OceanEyes]

Hey guys,

Quick question to make sure I'm thinking straight.
If I was diving twin SM with one tank at 21% and one at 33%, I'd set my computer at 27%?

Cheers, Mike

And of course not go deeper than the MOD for 33%

I fail to see the logic behind your overall strategy, and suggest that you seek training in decompression procedures and the protocols for switching from one breathing mixture to another prior to attempting to execute the plan that you propose.

Were you to attempt to proceed with your plan to switch from one cylinder to another, based solely on the usage of 10 or 20 bar in each bottle, you would need to pre-set both gasses into your computer, then select the specific gas that you are currently breathing on your computer with each switch. In your example, you would program both 21% and 33% on your computer, and make the required changes every time that you switched between mixes. You would not benefit at all from setting your computer to 27%, and hoping that everything will average out in the end. This would not provide you with anything like accurate information regarding your actual nitrogen loading, nor would it provide you with a reliable means of tracking your O2 exposure.

A dive made with your suggested protocols could be performed, but seems to me an exercise in obsessive gauge monitoring, would be needlessly complicated, and simply overloaded with potential opportunities for operator errors.

 

[Mike1967]

A dive made with your suggested protocols could be performed, but seems to me an exercise in obsessive gauge monitoring, would be needlessly complicated, and simply overloaded with potential opportunities for operator errors.

Maybe I should have given a bit more info.
It's not a deco dive. Depth won't be anywhere near MOD for 33%. My plan to swap regs is based on the fact that it's the procedure for diving SM.
It's not my desire to dive with unmatched mixes, it's just what happens to be in them. In this scenario I could just leave my computer set to air and enjoy the "buffer" so it's not a big deal.
Having said all that, I still think after the dive my nitrogen loading and O2 exposure would be the same, or that close it wouldn't matter, as doing the same dive with both tanks at 27%.
You're a PADI pro so you definitely know more than me about this stuff so I'm probably wrong, can you please give me something more than just because to support your opinion? Cheers