One thing I'd like to add to all this. I worked my way through college washing dishes. If they would let me, I'd go into the dish room and give each of the dishwashers $100 because it's such a crappy job that gets no thanks or recognition.
So doubling the tips is how I can get tips to all the people who we don't see, but are key to a great voyage. The dishwashers, the laundry, the cooks, etc.