Magnet-assisted automatic locking mechanisms for use on a sailboat are disclosed herein. One such mechanism includes: a housing having an internal space and configured to receive a slug that moves along a path through the housing, the slug being operably connected to the halyard, the housing including a first housing side and a second housing side coupled to one another; first and second flippers rotatably disposed in the housing, the first and second flippers configured to rotate between at least a cocked position in which the slug is inserted into the housing, a locked position in which a surface of the first and second flippers receive the slug and impede the slug from exiting the housing along the path, wherein the halyard is tensioned in the locked position, and a neutral position in which the first and second flippers allow movement of the slug; and a magnet assembly configured to effect rotation of the first and second flippers.