In fairness those courses are just specialisms within other subjects.
Watersports Sci and Dev could be a masters on a mechanical or aeronautical engineering degree and involve lots of studying/designing hydrodynamic testing etc on boats?
And don’t forget, the nurse at your gum clinic will have had to do a course in how to identify scrot rot, so someone has to offer it.
Hairdressing management, so youve been a hairdresser for X years and want to open a sallon, you’ll need to do accountancy and various other business courses, so why not do them all at once?
How many on here would do a bike shop management course before opening a shop? How often are there threads on here saying XYZ are crap. Those would be avoided if the owners went on said course? How much would someone on a hairdressing website mock that course?