If you consider it as charity, so be it. At least I like the idea of donating to people that make good effort to get it rather than donating to charity that I may not even know how much the actual money be filtered down to the real needy. I feel good about it, so do they from looking at their expression and how their are treating me.
Makes sense to me. I, too, would rather donate to people I see making a good effort to support themselves and maybe also avoid dealing unscrupulous or inefficient charities. I just wish there were a way to do it that is disassociated from a tip on my liveaboard.
In the end you do what you please. It is your vacation. If you don't feel right to give as much as other would, just don't do it. You already paid the whole expensive trip. What would they do if you don't tip at all? Deny you on booking your next trip?
I agree we will all do as we please. I already said in my first post above that I have been tipping 10% because that's what I understand (correctly or incorrectly) the generally accepted amount has become on Indonesian liveaboards these days. The rest of my comments are just pointing out the deficiencies in this practice.