Abstract: A course plotting device comprises substantially parallel first and second legs, substantially parallel third and fourth legs which are pivotally connected to the first and second legs so that they cooperate therewith to define a collapsible parallelogram structure, and a compass rose element mounted at the point of pivotal connection between an adjacent connected pair of the legs. The device is operable for plotting courses on a chart by aligning one of the legs with either a latitude or a longitude line on the chart and aligning one of the other legs with the desired course line. One embodiment of the device includes a vector element which is adjustably secured to one of the legs for plotting courses which have been compensated for the effects of winds and/or currents and another embodiment includes a pair of mirror elements which are operable for determining the relative bearing angles between remote objects.