Does the expectation of a tip by an instructor for teaching a student not raise the potential for a conflict of interest? I know you instructors here on SB are paragons of professionalism and all, and you'd never consciously let the prospect of a tip influence what you do, but it does make one wonder what might happen subconsciously.
I can't imagine my college professors, even in a class where I worked one-on-one with the professor, accepting a tip. Even the appearance of the potential for a conflict of interest seems like a good reason for those in the teaching professions to refuse tips.
I think it's entirely appropriate to tip any DM, skipper or crew on a boat on which the diver is doing his checkout dive with an instructor, just as one would if one were not diving as the instructor's student. But I just don't think it's a good idea for instructors to think they might receive tips from their students.
I think it's already been stated that most instructors don't expect a tip - but appreciate one when offered - be it beer, a dinner, or pocket change. It says to the instructor, "Hey - you did a great job and I appreciate your hard work!"
And frankly - my gross revenue - before expenses - from SCUBA make up less than 5 percent of my income. Tips make up less than 10 percent of my scuba revenue.
You don't need to worry about me corrupting my values, giving away certs, or being unethical for less than 0.5 percent of my annual income.