On some peak weekends we reserve all of our canoes for overnight trips. About one or two weeks out we'll open up the remaining inventory of canoes for day trip reservations. There are two main reasons we do this - day trippers tend to be a bit more picky about the weather (understandably) and are more likely to cancel trips based on weather forecasts. Requiring day trips to wait until a forecast exists helps tremendously. This also goes hand in hand with the second reason - day trips take away boats from overnight groups that we otherwise have to turn away. We have a very short season so every day we're able to get the boats on the water helps.