As someone who owns a boat and yet fishes out of the back of the boat, I have been in both positions about paying.
as a boater I will not accept money from an angler unless they need a ride to the lake, then I am altering my day to accommodate them. Which i do not mind I will NEVER accept anything over 20 no matter what the situation! as a CO i will never pay over $20 unless the boater does something special like go fish half the day in my spots ECT... This one has only happened once and i slipped the boater 50, he never asked for anything and never took a penny from me ever again.
Now i am going to be fishing rayovac and have heard the boaters expect the $$$ I will offer up some cash at the end of the day based on how the boater has been during the day.