Sea chart navigation plate - has top rectangular prim. carrier running along chart plate, and rotatable graduated sec. carrier

摘要

The navigation instruments comprises a flat rectangular plate, and a primary bearer consisting of an upper straight edge fitting on to and movable along the plate, and a lower guide attached at its ends to the ends of the straight edge. The lower guide moves via a guide in a track in the plate. A secondary bearer is fitted on the upper straight edge, and can move in the plate crossways direction, and a graduated plate is rotatably located on this bearer. It is also possible for the primary bearer to be movable in the plate crossways direction and for the secondary bearer to move in the plate longitudinal direction. A sea chart can be introduced under a plastic cover attached at the upper edge of the plate. The lower edge of this cover overlaps the lower plate edge for fixture at the rear. Heavy-weight plastic is used for the cover that the chart can be prevented from turning relatively to the plate. (Provisional Basic advised week 84/22).