It depends on when EMH at MK end. Usually, Illuminations is at 9, and you probably would be back to the dock around 9:30. If EMH are until 11 or 12, you could hop on the bus at Yacht and Beach Club and get on a few rides. If EMH end at 10, then no. If you're going during the Christmas season, then Illuminations is at 9:30, so you wouldn't get back to the dock until 10 or so.