Reasons drive solutions
EdIf you are taking the courses to just learn sailing skills, any of the schools would probably be acceptable. Whether ASA or US Sailing "accredited," or an independent. By law, all instructors taking paying students out on a boat must be USCG licensed -- most have the basic "six-pack" license (six passenger max on an uninspected vessel). ASA or US Sailing provides some degree of standardization regarding the course content and instructor training. And, because they represent de facto industry standards, their certificates are generally recognized throughout the charter industry. But, charter companies will recognize other paths to competency as well.Which gets to your intended use. If it is to bareboat charter in a particular area, then ask the various charter companies in that area what their minimum training/experience requirements are. If you are just planning to buy a boat & are getting prepared, almost any competent school will do.Whatever school you choose, affiliated or independent, compare the course content, the boat size used for training, the number of students in the class, the experience level of the captain/instructor, etc. The ASA or US Sailing course curricula are a good guide. The boat size used for the course should be appropriate for the type of sailing you expect to do -- if cruising, then at least something around 30 ft. The number of students will affect the amount of hands-on time you actually get. The USCG license says that the captain/instructor has a certain amount of sea-time & book knowledge, but verify whether the person is a racer, cruiser, blue-water sailor or whatever. Ask lots of questions -- be a pain-in-the-butt about asking too. If they tend to blow you off, then you can wonder if they'll do likewise out on the water while teaching. Not every good sailor is a good teacher. Many excellent sailors I know don't suffer fools/lubbers well.When I started some years back, I took the USCG Aux. basic sailing/seamanship course in the Winter, followed by a 20 hour basic on-the-water course (by a local, independent school on a Pearson 303) in the Spring. All that Spring/Summer, I rented boats locally for daysailing. I followed that with a USCG Aux. navigation/piloting course in the Winter. The next Spring I took the more advanced 20 hour cruising course, and more Spring/Summer daysailing. That Fall I did my first bareboat charter. Over the next two years I did two one-week coastal piloting/navigation/seamanship training cruises on the schooner "Ocean Star," collectively covering the entire New England coast from New York City to Mt Desert Island, ME. Plus much daysailing and other bareboat charters. "Ocean Star" isn't operating in that capacity anymore but here are various "offshore sailing schools" available to get that equivalent intense training.After a few years I felt that I had enough practical knowledge & insight into my capabilities/desires to actually select and buy a boat (Catalina 320).The point being that these schools are just the start on a long-term, lifetime process of education in seamanship. These forums, where we as a community of sailors share our knowledge, experience, and questions, are an integral part of that process.Good luck,--Ron