Should there be an "Advanced Nitrox" and "Rec Nitrox?"

[DevonDiver]

I think that the current dumbed-down courses should only qualify for standard 32 and 36% mixes. That's all the majority of divers really need.... and that limitation is fair given that shorter modern courses don't teach principles like EAD, manual calculations (Dalton's diamond) etc....

A second course that taught the extra (now excluded) elements would qualify for custom mixes up to 40%.

Beyond 40% is technical diving. There's no reason why a separate tech level nitrox course is needed.... it can be incorporated into technical training quite easily.

 

[Steve_C]

I did SDI computer nitrox. With the course came the SDI Nitrox tables. In the course we discussed different mixes up to 40. I supplemented the tables with a line for 1.3 and 1.2 since I like to dive a lower PO2 that 1.4. I see absolutely no difference knowledge wise between diving a custom mix or limited to 32/36. You get your bottle. You test it. Often it is off a bit from what you asked for. You check the MOD and if it is ok to dive that mix you set your computer accordingly. If not, you have the shop adjust the mix. Many of the places I have bought the nitrox custom blend. Some have banked 30%. Since I am never sure where the next dive will be, due to weather etc., I tend to always fill to 30% unless I know the next several dives are ok for 32%. Dive shops have told me they try to err on above side. If the customer aks for 32 and they get 32.3 they never complain. If they get 31.8 some will complain although both are within margin of error.

I no longer check MODS from the table, now that I have an APP that does it for all mixes from 20 to 40 but carry the table with me. With my diving the clock is not an issue but I am aware of it.

 

[drrich2]

"A lot of times I do not understand why dummified versions of the same thing are taught to recreational divers with chunks of useful information skimmed over or missing from the curriculum."

Because the so-called 'dummified' version meets the needs and desires of a large segment of the recreational diving public, enabling them to safety engage in what they wish to do. Anything beyond that, no matter how intellectually interesting to some others, is outside the goals of many of these divers.

Many people want to accomplish their objectives as fast, cheaply & easily as practical. Most don't mix their own nitrox, and you hardly need fluency in calculating mixes. A table/graphic with a listing of MODs for different mixing can quickly tell you how rich a mix you could use, though I believe most divers use banked rather than custom mixes anyway.

"In other words, that course without Decompression Procedures course is really not a technical diving course. It is just the proper way of teaching Nitrox. should that level of education not replace the diluted courses that are being taught as "Rec?""

Not necessarily 'proper,' no. 2 OW divers take a recreational nitrox course and head to Bonaire for a week of shore diving, with EAN 32% bundled into their dive package at no added charge. Later they take AOW, and dive out of Jupiter, Fl, diving EAN 36%. Then later, they dive the offshore wrecks out of North Carolina with the popular mix of 30%. One of these divers took a regular mainstream recreational nitrox course; the other took your more advanced/inclusive course, and had to work harder, study longer, maybe pay a little more...for what?

These 2 guys went the same places, dove the same nitrox mixes, had the same MOD and NDL limitations, and had the same good times with no deco. violations & stayed above their MOD's. Neither is headed for technical diving.

However interesting some people may find the added content, or how much they may appreciate a more in-depth understanding, or remembering some gas law or knowing how to mathematically calculate a custom mix...for a large portion of the diving public, that's worthless. They don't care and won't use it. Why put them through that, when those who do value it can take a more advanced course?

Richard.

 

[DevonDiver]

As with many things in diving, it's all about how many tools you need/want in your competency tool set.

I'd suggest that the vast majority of divers need nothing more than the competency to use 32 and 36%. That can be covered on a very quick and simple course.

A smaller percentage of divers might need/want to use custom blends >40%. That comes with manually calculating MODs, EADs, PPO2s, Best Mixes etc... That can be covered on a more extensive course.

A very small percentage of divers might need/want to use deco blends >40%. That comes with an in-depth understanding of all things nitrox,especially oxygen handling and equipment considerations.

Where the system generally fails at the moment is to cater for those divers in the middle bracket. They only have a choice of a very simple course, or a very extensive course.

 

[Steve_C]

I'd suggest that the vast majority of divers need nothing more than the competency to use 32 and 36%. That can be covered on a very quick and simple course..

and 30 and ... Dove 34 once when a shop blending me 32 gave me 33.7 and that was within my 1.3 MOD.

 

[seeker242]

A lot of times I do not understand why dummified versions of the same thing are taught to recreational divers with chunks of useful information skimmed over or missing from the curriculum.

I would say it's probably because people have different ideas about what is considered "useful" to begin with. For example, what use are manual calculations if you will only ever just use the dive computer to do the math?