6. orientation of the RCDS display to other than chart-up, may affect the readability of chart text and symbols (e.g., course-up, route-up);
.7 it may not be possible to interrogate RNC features to gain additional information
about charted objects;
.8 it is not possible to display a ship's safety contour or safety depth and highlight it on the display, unless these features are manually entered during route planning;
.9 depending on the source of the RNC, different colors may be used to show similar chart information. There may also be differences in colors used during day and nighttime;
.10 an RNC should be displayed at the scale of the paper chart. Excessive zooming in or zooming out can seriously degrade RCDS capability. For example, by degrading the legibility of the chart image; and
.11 mariners should be aware that in confined waters, the accuracy of chart data (i.e., paper charts, ENC or RNC data) may be less than that of the position-fixing system in use. This may be the case when using differential GNSS. ECDIS provides an indication in the ENC which allows a determination of the quality of the data.
3 Member Governments are requested to bring this information to the attention of the appropriate Administrations and all seafarers for guidance and action, as appropriate.
