Abstract: An adjustable sissy bar device for a watercraft such as a jet ski, is provided. A mounting member is coupled to the jet ski about the stern and below the seat of the jet ski. A bar mount is coupled to the yoke. A bar is provided located extending along the stern of the jet ski upwards behind the seat. The bar moves between an upper position, where it forms a backrest behind the jet ski, and a lower position, where it allows a rider to more easily reboard the watercraft from the stern. Removable lock pins extend through the mounting member and the bar to secure the bar in a selected vertical position. Plural vertically arranged apertures in the bar permit the bar to be secured in a plurality of vertical positions.