The one part that I don't like about NAUI is the unknown consistency of the instruction due to the potential unknown, not quality controlled, added content by the instructor. Two divers that had two different instructors could have taken completely different courses, but both are issued the same certification. It can even happen with the same instructor. He/she could certify two different divers with completely different courses. I understand that all of the basic scuba skills are covered in each instance.
Aside from the question of different people and different classes having different needs that are best accommodated in a flexible fashion with an enforced minimum, why would you want everyone to be forced to exactly the same level? Your description of the NAUI system as "unknown consistency" is horse pucky. NAUI standards assure that a minimum (that is, might I point out, in excess of PADI's maximum, including as it does rescue skills that are excluded from the PADI curriculum) suite of required skills is completed and that other skills deemed necessary and appropriate by the instructor are added. At an absolute minimum a diver trained to NAUI standards has slightly more training than a diver trained to PADI standards and, at the maximum, a NAUI trained diver is an AAUS Scientific Diver or even a Navy SEAL ... this appears to be a problem for you, for the life of me I can not see why. Is it because you can't tell the difference between such divers without seeing a different card?
Back to the OP...
Within PADI, yes the modules of the class have to be completed in order; however, the skills within the module can be completed in any order. Also, certain open water dives/skills cannot be completed until certain modules of the classroom and/or confined water are completed. The module order is important because the student can use multiple instructors/locations to complete his/her dive training. Each instructor signs off the completed module; therefore, the next instructor doesn't have to guess where to pick up and that instructor knows exactly which skills have been completed.
So what? That is only meaningful if someone is moving from one shop to another shop in mid course. All the university courses that I was involved in were team taught, we changed students at least twice a semester, sometimes three times, for pool work and every two open water dives. This created no confusion or difficulty, in fact, it enhanced the student's progress because different instructors had different outstanding attributes (e.g., I got students who were having trouble with their free diving skills, esp. breath holding, because I was the best in the group at teaching that area. Other instructors had other specialties and students could be grouped by need). All that requires is good records and short conversations ... no biggie.
For the most part, doing the skills in order of the modules makes sense. Partial mask flood comes before mask remove, replace, and clear; therefore, it makes sense. More complex or involved skills come later once the student has spent time in the gear and water and has completed some of the basic skills; therefore, those make sense. There are only a couple of skills that really don't make too much sense on "why do I have to do it here, instead of there" aspect.
There are many different "sensible" ways to order skills, no one way is best each and every time, except on average. Taking the average approach only assures regression to the mean and suppression of above average students and instructors ... pity, it is such a waste.
I know many people out there complain that PADI has this rigid order in which you have to complete the skills, but I would be willing to bet that most non-PADI courses follow pretty closely to the general skill order because it makes sense.
Do you really believe that? I would dispute that statement.
NAUI Instructors don't have to use NAUI books. They can use a book from the 70's and as long as their students meet the minimum standards in skills and knowledge they can get certified. The academic freedom IMO is the ability to use all your own teaching materials if you wanted to.
Yes, it does not make book sales another cost center. I use the NOAA Manual, it is many years and many dives before student need to buy another book, and then it is often just a newer edition of the NOAA Manual.
I know of an instructor who loans books or has his students check them out at the library because he genuinely teaches as a hobby and looks to save his diver's money. He uses a very old non-scuba agency book too and fills in the gaps with a whiteboard and pen. His students come out just as competent as any other.
I'd bet that they're objectively more capable.
