A portable boat mooring system is provided that includes a base removably or non-removably attached to a pier. An arm assembly can extend from the base outwardly beyond an edge of the pier. A mooring line that has a resiliently flexible portion thereof attaches a boat to the system while mooring the boat to the pier and maintaining a space therebetween. A tool-less hardware assembly can be utilized which allows users to manually install the base to the pier while they remain on top of the pier or above an upper surface of the pier during the entire installation. An anchoring device can selectively hold the mooring line at a predetermined length or state of tension.