The ferry is one of the oldest symbols associated with death. It signifies transition, often from the physical realm to the spiritual. We may be undergoing a spiritual 'death' or change of some kind, moving on from present knowledge. The old idea of being ferried across the River Styx, the boundary between life and death, gives an image of making major change, when we may have to leave behind all that we have known. To dream of being on a ferry indicates that we are making some movement towards change. Because the ferry carries large numbers of people it may also represent a group to which we belong needing to make changes, needing to change its way of working and take responsibility for moving as a group rather than as individuals. You might like to consult the entries for Boat/Ship and Death.