rstofer
Contributor
If you are new to diving, often it is hard to learn things as you don't know anybody more experienced to teach you (this was my experience). So many new divers keep paying for courses that are most likely unnecessary. However, look around for clubs/people that are happy to mentor new divers and you can get a lot of help without course fees from others (this is my approach now!). Many skills can be learned easily from a more experienced diver, as opposed to doing a course about it (night, drysuit, navigation PADI-style specialty classes come to mind...)
My concern about the mentor idea is that you can only learn what they know. You don't get the benefit of a fully reviewed course of instruction. There's no written material and no knowledge reviews. Now, if that mentor happens to be an instructor and the instruction happens to completely follow a known course of instruction then you get a bargain. More often than not, it's "just do what I do".
Around here it doesn't matter what your buddy teaches you about Nitrox, you can't get a fill without a recognized card. Same thing with deep and night dives from charter boats; no card, no dive. For these types of dives, an AOW is usually adequate.
One thing about our litigious society, we practice self defense. Businesses implement policies that attempt to keep people from hurting themselves.
I'm not a fan of the 'mentor' concept. It might be useful for polishing skills but I don't think it is a good substitute for more formal training.
Richard