You can always walk over to the Swan and take the boat directly there. The walk to the Swan boat dock should only be about 5 minutes and the boat doesn't make any stops before going to MGM, probably a 10 to 15 minute ride. You also will have to walk from MGM's boat dock to the entrance of Fantasmic, which will be at least another 5 minutes. It will might be easier just to walk. I've read about a short cut from the BW to the MGM path. I think you cut through somewhere around the swimming pool. You could post a seperate question about that on the resorts board.