One-way rentals in the Mediterranean

Hi everyone! I get a 1-month sabbatical with work and I'm planning to take a pretty big trip. I'm planning for this to mainly a Europe trip around the Mediterranean coast (Spain, France, Italy).

I would like to sail for some part of the trip, preferably a one-way rental between some of my destinations. Does anyone know of a place where I can get a one-way rental if it's at all possible?