If a ghostly ship is moved by an outside force into a fog bank, does the resetting of Ghost Ship (since it doesn’t seem to be a “continuously active” ability) cause the ship to become lost in the fog bank before the controlling player can “ghost” out of it and ignore the fog bank?
Ghost ship’s terrain ignoring effect only applies when moving, so as soon as it stops on the fog it becomes “lost” like any other ship would, regardless of how it was moved there. When the ship’s owner’s turn comes back around, if they give it a move action, it exits normally (roll & place) whether they turn ghostly on or not.
If they do turn ghostly on again, after placing the ship on the edge of the fog it could immediately double-back over the top without falling back in, unless it stops on it again.
Activating ghostly while already in a fog bank won’t do anything on its own. The ship remains “lost” until it moves.