NAV 44/7/6
5 Because official charts are used
in RCDS, mariners can be assured of the same high levels of
reliability, quality and acceptance of liability that
national Hydrographic Offices provide for both their paper
charts and their ENCs. Like official paper charts and ENCs,
RNCs are backed by a comprehensive update service, which
ensures that they can be kept up to date.
Performance Standards
6 Proposed Performance Standards
for RCDS were discussed at NAV43 (NAV43/WP.2). Because a
number of concerns were expressed about the system, the
Sub-Committee felt that further investigation was warranted.
7 The sponsors of this paper fully
support the view that any genuine safety issues associated
with the use of RCDS should be thoroughly investigated and
have taken action to obtain additional feed-back from users
on the specific topics raised at NAV 43. There is now an
increasing number of RNC users available to provide this
feedback.
8 Draft RCDS Performance Standards
which take the form of either a stand-alone document or an
RCDS Appendix to the ECDIS Performance Standards (Resolution
A.817(19)) have been prepared by the IM0/IHO Harmonization
Group on ECDIS (HGE), and the IHO respectively. The proposed
standards call for the use of official raster data in an
ECDIS in circumstances where ENC data has not yet been
produced.
9 An important benefit of“dual-fuel”is
that sophisticated electronic chart navigation relying
entirely on official, government backed and up-to-date,
electronic charts can be provided immediately for almost any
voyage. The alternative is for mariners to wait some years
more before ENCS are available for many areas of the world.
Feedback from RNC Trials
10 A growing number of vessels of all
types and classes, now use raster chart systems. These
vessels operate throughout the world under a wide range of
navigational conditions. A number of these vessels are being
used by the sponsors of this paper to evaluate RNC
navifgation and RCDS.
11 Based on the experience gained
from the sea trials, it is clear that mariners believe that
the continuous display of a vessel's position on a chart
image is of great benefit. In particular, a number of high
speed ferry operators find that RCDS provides the real-time
navigation display which is essential for the operation of
their vessels. Automatic plotting also frees the mariner for
other important navigation-related tasks such as maintaining
a safe lookout and collision avoidance.
12 One important difference between
ECDIS and RCDS is that RCDS does not enable the selection or
removal of layers of data, nor does the RNC data
itsel ftrigger automatic alarms and waming's. However, RNC
users report that this is not a problem, as the equipment
provides the capability for critical areas and safety
contours to be highlighted manually to trigger appropriate
alarms. This is a significant advantage over the paper chart.
13 The system only displays a portion
of a chart at any one time However RCDS like ECDIS minimises
this effect. In particular, it is possible to call up smaller
scale charts (providing a larger viewing area) or larger
scale charts (providing more detail) almost instantaneously
and all charted notes can be reviewed simply and quickly,
irrespective of their position on the chart. As an extra
safeguard, the proposed RCDS Performance Standard calls for a
limited number of paper charts to be carried and used as a
reference during a voyage.
I:/NAV/44/7-6.WPD
