They offer, I take it! Of course if its just a dinner cruise I won't, but if we burn a tank (which we usually do) I take it and thank them. Call me a meiser but we paid for everything else, Skis, wakeboards, surfboards, ropes, vests Insurance, maintenence, etc... they can throw in a $20 for an awesome day on the water. I ALWAYS make sure my guests have a great time! Thats cheap entertainment. Now that most of my friends have boats they are starting to get it. Owning a boat isn't cheap.