Free: Contests & Raffles.
100 to 150 what? Pheasant,quail,chucker or???
They can be pretty skittish late season and often flush well out of range. Did you see others there while you were hunting? It is less common for people to access by boat but there are certainly those that do. Chances are, if its public it will have been hunted to some degree. Try to take andvantage of the weather. Sometimes fresh snow can make the birds hold tight during the late season. Also a deep freeze can open deep marsh that you may not have been able to access previously.
I've always had birds hold better for me the colder it gets. Those boat access only places get hunted for big game, but not many people put in the effort for birds. If the draws you saw birds in are the only decent cover in the area, the birds will be there in December too.