Here is my concept of Charon done for the Gnomon Workshop forum challenge.
After exploring this topic and trying different ideas I have decided not to go far away from the original ferryman's location and function. Instead I went for a little twist. I literally merged him with the boat, so they create one body. I also thought wings could serve as a sail. I have read that Hades was divided into different parts depending on merits or wealth of corpses. I chose the least exclusive, dingy, but very economic option of transporation. I also created short psychological profile for The Ferryman - he must have been a real freak!!! (or maybe he is...)