| 摘要 |
The navigation device is for determined directions and positions on a sea chart and comprises a cylindrical tube (1) in or on which the chart is rolled. Located on the tube is a runner (4) provided with a graduated scale (6) and position marking (7), which is movable both along the tube longitudinal axis and in its peripheral direction. The runner comprises a transparent tube part provided with the same curvature radius as the tube. The tube part is flexible and is maintained on the tube by clamp effect. The graduated scale is circular and the runner position marking comprises a hole made in the scale centre, a colour marking or a pin. A wire or similar is fixed in the position marking. The cylindrical tube is transparent and the chart is maintained against its inside by means of one or more flexible retention components. |
