NAV 44/7/6
14 As with ECDIS, RCDS provides
different colour schemes for use during the day, night, dusk
and dawn, enabling the RCDS display to be clearly viewed
under all lighting conditions.
15 Some of the evaluation trials have
used ECDIS equipment in the“duel-fuel”mode of operatron,
using vector ENC data when it is available and using raster
RNC data where it is not. Of particular interest are the
container ships operating between Singapore, Hong Kong,
Southampton and Rotterdam which use vector ENCs Specified in
the ECDIS Performance Standards in these four ports and their
approaches, and official raster data for the remainder of the
route. Mariners involved in these evaluations report no
difficulties when switching from vector to raster data and
vice versa.
RNC Product Specification
16 The need for an RNC Product
Specification was identified at NAV 43 . This has now been
prepared by the International Hydrographic Organisation.
Advantage of RCDS over paper charts
17 As well as allowing continuous
automatic plotting of a vessel's position, and the provision
of alarms and warnings, RCDS has several advantages over the
paper chart. Allowing for differences between chart datum and
WGS 84 can pose problems for mariners and lead to mistakes
when using paper charts. The correct datum shift values are
encoded within the RNC data and are therefore applied
correctly and automatically by an RCDS.
18 A further advantage of RCDS is
that Notices to Mariners are supplied on a regular basis in a
machine-readable format, enabling rapid and accurate
corrections for which Hydrographic Offices accept
responsibility. Port State Control inspections show that on
many ships paper charts are out-of-date and not corrected.
19 The ability to transfer positions
and user-entered data automatically from one chart to
another, and the ability to amend waypoints almost
Instantaneously, makes passage planning much quicker and
easier to perform and control, particularly when a mixture of
Mercator and Transverse Mercator charts is involved.
ENC Production
20 It is wrong to suggest that taking
information directly from an existing paper chart is
sufficient to create an ENC that will support all the ECDIS
capabilities. An ENC provides more data and Information than
is found on a paper chart. To compile an ENC it is often
necessary to re-evaluate the source survey data. This is much
more involved than simply copying the existing Paper chart.
21 The adoption of RCDS and the use
of RNCs will not slow down the production of ENCs for use in
ECDIS. Hydrographic Offices are under constant pressure by
both commercial shipping organisations and navies to produce
ENCS as soon as possible. The member States sponsoring this
paper see RNCS as an interim solution and they are fully
committed to creating ENCS as soon as possible.
22 In those countries where ENC
production is well advanced the proposed RCDS Performance
Standard will not be relevant, because the ENCs, which are
acknowledged as being superior, will already be available and
must be used in ECDIS.
I:/NAV/44/7-6.WPD
