The Rule of Two - one to solve, the other to make

Now, one often hears the term Riddle Master used to describe those who excel in the art of Riddle Games. But I judge the title differently as I have often been called a Riddle Master and yet, paradoxically, am atrocious at answering riddles myself.

Hence I say that there are two kinds of Riddle Masters: the riddle-solver and the riddle-maker. One can be both, of course, but if not, then it is the riddle-makers' task to train the riddle-solvers' in answering, and the riddle-solvers' task to challenge the riddle-makers' in creating.

I, of course, am a riddle-maker, and have trained all those interested in both the skills of answering and and creating - for to be one allows a unique perspective as to the other and, in my experience, riddle-makers are the rarer of the two kinds of Masters.

How might a ferryman leave his boat, yet leave the ferry operating = ?

Here is a hint, written by Neil Gaiman: only tell the ferryman the answer from a safe distance.

Beware another Riddle Master