I have been interested in some of these additional classes from SSI. I realize that there are several agencies and all recognise the level of divers somewhat differently based on their own particular requirements. When I was living in South Africa only PADI existed and there was not really any other options or credible choices. When I moved back to the states there were lots of options. At my local Dive shop which is SSI, that became my only real option here in Eastern Wa. I'm not at all curious about which agency is better or which is preferred or such. That will be mostly personal opinion and for the majority only having experience with the agency or organisation they chose. I'm just sharing the level of training and skill needed with SSI for anyone interested.
I have taken 4 optional advanced classes now. They are sold, not free to take. It's a business after all! One of them is called the Science of Diving. It takes 10-12 hours of on line class and then there is a quiz at the end of every segment. The quiz questions range in difficulty from very easy, to quite mathematically complex. Also a fair amount of facts and " physics laws" to either memorize or truly understand.
There are 8-10 questions on each quiz and you can only make one mistake to pass the quiz. However I recall somebody saying you could miss 2 and still pass? that may be true, but I know that I had two wrong on one quiz and it told me I failed? The Science of diving is their longest most all inclusive on line class. I finally completed it a couple weeks ago.
While at the dive shop I asked about the on line status change for the classes that have been passed, the shop owner told me you don't get credit until you pass the exam. I replied I passed all the quizzes on line and it said " congratulations you have completed the course" He replied, but you did not pass the exam yet. You have to do that here, it's a 100 question test! Wow..... I was both surprised and actually impressed that this is not just something you pay for and they hand it to you. There is a fairly strict level of knowledge required before this can be completed. This on site written exam is compulsory for all the on line training courses. Although this one is the longest exam they have.
I have not actually gone in to take this exam yet, I figured I better go take the quizzes again and verify my certain knowledge of all the content! I must say that I have a new found respect for the SSI organisation to go this far to be certain that the person getting credit is actually taking the tests closed book on site to prove they know the material!