A folding propeller for a boat, e.g., for a sailboat or a multihull yacht, and a method for installing and/or adjusting such a folding propeller, where said folding propeller has a hub for directly or indirectly fastening at a driveshaft connected to a motor, where said folding propeller further has at least two individual blades, where each of said blades has a root arranged to pivot around a pivot pin at said hub to be either in a first, operative position, where the blades are pointing mainly in a radial direction, and in a second, inoperative position, where the blades are pointing mainly in an axial direction, where said hub has one or more cut outs for said blades roots and further has a first set of holes for installing said pivot pins and a second set of holes for installing a locking device for engagement with said pivot pins.