Abstract: A wind and course calculator for navigation is provided comprising two superimposed disks made from a transparent material, a mobile disk 1 movable in rotation and in translation carrying a network of concentric circles corresponding to the speeds and of converging straight lines corresponding to the angular values of headings and a supporting disk 2 having a mark 5 indicating the heading and, at its periphery, graduations corresponding to the angular values of sailing trims of the boat and a scale of speeds 7 carried on the radius directed towards the indication of the heading, on the reverse side of which supporting disk is fixed a pointer 10, 11 having a slider 12 carrying a reference dot 13 serving as display and reading point. The upper face of the supporting disk has two parallel guides 3 between which the mobile disk 1 slides.