Steve should be along soon and have a definitive answer to this question.
Thanks Walter... and apologies to the OP for taking so long to answer... my excuse is that I have been on the road.
First off, the short answer the the main question.
An SDI instructor must be affiliated with an SDI facility to order materials and register students.
Now some further details. As an agency, we are not opposed to independent instructors. Remember our genesis was TDI and my guess would be that better than 60 percent of the first several hundred ITs and senior instructors for that branch of our organization were and still are independent... (I was one of them before joining HQ staff by the way.) Independent ERDI instructors are also accepted, so we DO support the concept of professional instructors concentrating their efforts on delivering top-quality diver education...
So why the difference with SDI? Support for the student predominantly. We feel that a beginning diver is better introduced to this pastime in the construct of a "proper facility" with classroom, bathroom, quality rental gear and so on.
Now, some of the functioning independent sport instructors reading this may now be thinking to themselves that they can supply this without the business and personal "hassles" of partnering with a full-service dive shop. That's great. We have an option for you. SDI has several levels of facility. (
You can read about them here.) AND
registering a facility is free with SDI. SDI, TDI, ERDI do not charge facility registration fees.
So if you are a working instructor who is serious about dive education and who presents a professional profile to your customers, then the solution maybe SDI.
If you are an instructor who just wants to work out of the back of a pickup truck and function without the benefit of a business license and some backup, SDI may not be what you're looking for.
With regards the questions about profit margins and profit sharing. SDI is in the business of publishing educational materials and supporting our members (all of our members including facilities and instructors) so that they can run successful business operations. We have a consulting department which can help develop business and marketing plans for our members. We make our materials, registrations and membership fees as reasonable as possible, so that businesses have a better shot at being successful, but we don't negotiate working conditions or relationships... sorry!
And the last question I think was about "something negative" happening should an instructor not "meet the shop's demands."
It would be necessary to have all the details and circumstances because this sounds like a grievance situation and not for general debate in a public forum. In general terms though the answer would be no as long as no standards or code of ethics violations have been breached.