We just finished installing a brand new Beachcomber hot tub for our guests to enjoy.  When entering the hot tub flip the cover open.  When in the tub stand the cover up on the far ledge of the tub and lean it against the large wooden post.  At the top of the post you will find an arm on a hinge.  Rotate the arm down in order to secure the cover against the wooden post.  When you are ready to leave the tub simply flip the arm back up, pull the cover down over the hot tub.  When exiting simply flip the cover back down in order to cover the entire tub.   The YouTube video, Using the Hot Tub, provides a visualization of these steps.