However, the RCDS mode does not have the full
functionality of ECDIS.
2. Mariners' attention is
therefore drawn to the following limitations of RCDS:
1. RNC data. itself, will not
trigger automatic alarms (e.g. anti-grounding). However,
some alarms can be generated by the RCDS from
user-inserted information. These can include:
clearing lines
ship safety contour lines
isolated dangers
danger areas
2. Horizontal datums and chart
projections may differ between RNCs. Mariners should
understand how the chart datum relates to the datum of
the position fixing system. In some instances. this may
appear as a shift in position. This difference may be
most noticeable at grid intersections and during route
monitoring.
3. Chart features cannot be
simplified or removed to suit a particular navigational
circumstance or task at hand. This could affect the
superimposition of radar/ARPA.
4. Without selecting different scale
charts, the look-ahead capability may be somewhat
limited. This may lead to some inconvenience when
determining range and bearing or the identity of distant
objects.
5. Orientation of the RCDS
display to other than north-up. may affect the
readability of chart text and symbols (e.g., course-up,
route-up).
6. It may not be possible to
interrogate RNC features to gain additional information
about charted objects.
7. 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.
8. Depending on the source of
the RNC, different colours may be used to show similar
chart information. There may also be differences in
colours used during day and nighttime.
