Take the route shown to you on the map from Fourwinds. It is by far the easiest and the bog is nowehere near to the track that runs to the circle from Batworthy corner. I have been up there twice in the last three weeks and had no trouble. There are three nice clapper bridges to cross the rivers and the Tolmen stone is also worth a look at if not a climbe through. It is on the opposite side of the Teign from the wall that runs from Batworthy corner so is easy to find.
Have a good trip it is a great place.

Peace Lubin.