Have not seen this done before!

[jadairiii]

I think most new divers would be totally confused by nitrox if they learned as part of OW. .....

Oddly enough, GUE Rec 1 students dont seem to have an issue with it.

 

[MichaelMc]

If we were to introduce EAN32 or 35 on two or three existing dives with a hard bottom at 70' that we supervised, replicating the OP's circumstance, what would be the key points divers need to understand?

First the OW topics:
- Nitrogen from your breathing gas dissolved into your tissue can lead to decompression sickness depending on its concentration in the gas, your depth, time, and ascent profile.
- The partial preasure of a gas depends on concentration and depth

Now the nitrox:
- Nitrox reduces dissolved nitrogen by replacing some nitrogen with oxygen in your breathing gas.
- For a given dive, this reduces the risk of decompression sickness.
- Oxygen partial pressures higher than 1.4 expose you to risk of convulsions underwater.
- For EAN32 that PPO2 occurs at 110', the MOD, for EAN35 at 98'.
- You must analyze your gas to verify O2 concentration, look up the associated MOD, and ensure you do not exceed it.

What is missing?

I've skipped pulmonary toxicity, extending bottom times, best mix, and history, but we're not yet issuing them a Nitrox card, just starting the Nitrox instruction.

ETA: I left off setting their dive computer or looking up their max time in tables, but the intent is that they dive air tables.

 

[kelemvor]

If we were to introduce EAN32 or 35 on two or three existing dives with a hard bottom at 70', what would be the key points divers need to understand?

First the OW topics:
- Nitrogen from your breathing gas dissolved into your tissue can lead to decompression sickness depending on its concentration in the gas, your depth, time, and ascent profile.
- The partial preasure of a gas depends on concentration and depth

Now the nitrox:
- Nitrox reduces dissolved nitrogen by replacing some nitrogen with oxygen in your breathing gas.
- For a given dive, this reduces the risk of decompression sickness.
- Oxygen partial pressures higher than 1.4 expose you to risk of convulsions underwater.
- For EAN32 that PPO2 occurs at 110', the MOD, for EAN35 at 98'.
- You must analyze your gas to verify O2 concentration, look up the associated MOD, and ensure you do not exceed it.

What is missing?

I've skipped pulmonary toxicity, extending bottom times, best mix, and history, but we're not yet issuing them a Nitrox card, just starting the Nitrox instruction.

In this scenario, I don't think they need to understand any of that. Unless they're using mixes richer than 40% or they brought a shovel, pp02 is a non-factor for those dives. All of those things might be good to know, but the knowledge isn't going to prevent an accident in the given scenario. OP said the dive company provides some sort of nitrox briefing. For divers who don't know how to dive on their own (according to OP they couldn't operate their computers) the additional information is just going to add confusion with no benefit.

 

[Magnus Lundstedt]

I think that Nitrox could be included in OW or AA/AOW levels, nitrox is not rocket surgery.

But i think some of the different opinions sources from different views of what basic scuba certification is.

If I look at PADI/SSI or equal OW certification in a holiday environment, it is usualy superficial and quick.

VCS is you get the literature to read by your self when you sign up. Then you have about one hour of theory class whit exam where the instructor helps you through the exam. Then two dive "confined" in the ocean from the beach, whit skills and then two dives in ocean, from beach or from boat.

What I seen from most "club oriented" organissations like SSDF (sweden, cmas member) is a more in depth education. with a number of theory classes and a number of pool sessions (at least 4*45 minutes) followed by at least 5 dives in open water.

What i seen from the PADI instructors back home is that they also give a much more in depth education than what I have seen in the VCS in low cost vacation environments.

If I have VCS in mind, some students would understand nitrox, others would not. If i have the more in depth education in mind i don't see any reason not to include it.

Interesting is that the PADI/SSI OW cert says that you can go diving together with another OW certified diver, while the SSDF/CMAS one star says you can dive under supervision of a dive leader, while i think it should be the other way around ;-)

 

[Firebar]

One other point to note. Although Ocean Diver is a full diving qualification - basically PADI OW. Clubs ensure members at least progress through Sports Diver. Most clubs don't regard the Ocean Diver qualification as a sufficient level for club diving. Ocean divers are managed by the club, normally diving with very experienced Sports Divers, Dive Leaders (DM), or Instructors. Under controlled environments, Ocean Divers are encouraged to dive together.

I’ve just gone through this, did Ocean Diver in March and finished Sports Diver on Saturday. I’d say that the level of Nitrox in Ocean Diver was pretty simple: advantages and disadvantages, calculating MOD, O2 cleaning, etc. Of course this is all on air tables / computers.

Sports Diver I found a bit more involved, more table work, bringing in decompression stops and the effect of Nitrox upon them. The maths isn’t hard, it’s making sure you know why you’re doing them though.

On the subject of support for Ocean Divers I felt that after the course I was competent to the level of guided dives, but with more time after that and support from more experienced club members that improves over time. I just wish I had more time to do more dives!

 

[stuartv]

If we were to introduce EAN32 or 35 on two or three existing dives with a hard bottom at 70' that we supervised, replicating the OP's circumstance, what would be the key points divers need to understand?

I agree with @kelemvor. In that example, I think all the diver needs to understand (beyond what is included in a PADI/SDI/SSI OW class) is how to know what the FO2 is of the gas they will be diving, and how to set their computer correctly for that.

 

[Cyborg Pirate]

We were in Bora Bora just shy of two years ago. We used Bora Bora Dive as the dive op for our dives there in Bora Bora. They were highly recommended by our Boat captain (we chartered a catamaran for 10 days and travelled to 5 different islands) Top dive was the op on most of the other islands. Because we were a private group of 6 and all Nitrox certified.... We never saw the practices of what the OP is posting about. I will tell you the there was a marked difference in the two dive ops tho. Bora Bora dive far superior

 

[Kharon]

SDI teaches computer use. SDI requires a dive computer. SDI OW divers are only certified to dive with a computer.

An SDI instructor has the option to teach tables as well, if they want to go above and beyond the standards.

First, never said SDI OW didn't ALSO teach computers. Only certified to dive with a computer - nonsense. ==> Ignore.

 

[Kharon]

Are you sure? I am not a SDI instructor, but I thought SDI was the very first major agency to go to computer training for OW. They sure took a lot of heat on ScubaBoard for that about a decade or so ago.

My course intensively used tables, both OW and Nitrox. Computers were covered much less. Not everyone will buy or can afford a computer. You get the tables with the manual and course.

 

[Doby45]

My course intensively used tables, both OW and Nitrox. Computers were covered much less. Not everyone will buy or can afford a computer. You get the tables with the manual and course.

Just because that is the choice of the instructor you used. Tables are not mentioned anywhere in the class unless your INSTRUCTOR chooses to mention them. SDI is strictly taught on computers, unless YOUR INSTRUCTOR chooses to add tables. The key here is YOUR INSTRUCTOR, do not infer that SDI as a whole is that way. Which is what you did. For the record I am an SDI instructor also.