You don't need a boat. The ducks will fly over the land somewhere. The only way you are going to know where the ducks are flying is to spend some time there. I have scouted lakes for two years before being able to have 5 or 6 spots to hunt that I know I will see ducks. Here are a couple of suggestions on where to start looking for spots. Where a river or stream comes into or goes out of the lake. Look for ponds that are close to the lake. Go to these types of areas ( if there are any like them) and set up . I would only take 6 decoys and mainly try just pass shooting until you find out where the ducks are flying. Go light sometimes I would move 10 times in a day.