486
Display,StandardDisplayandAllOtherInformation
(IMO Resolution A.817(19) and/or IMO Resolution
MSC.232(82)).
TheBaseDisplayisthebasicdisplayprovidedby
theSENCandisrequiredforallcharts.Itisthebasic
datathatcannotbealteredbytheoperator.
The Display Base contains information on
coastlines,
safetycontours, dangerindications,traffic
routing,scale,range,orientationanddisplaymode,as
wellasunitsofdepthandheight.TheDisplayBaseis
notintendedtoprovideenoughinformationforsafe
navigationjustbyitself.
The Standard Display, which is also a pre‐
arrangedchartdisplay,butwhichcan
bemodifiedby
theoperator,andwhichisautomaticallyshownwhen
theECDISisfirstswitchedon.Itcontainsthedisplay
base plus boundaries of channels etc., conspicuous
features, restricted areas, chart scale boundaries and
cautionarynotes.
The operator can modify the amount of
information displayed for the purposes of route
planning and navigationalmonitoring. The operator
decideswhatlevelofinformationisdisplayedduring
any particular situation or task. However, when
working with these other levels of information
display, an operator must immediately be able to
returntothestandarddisplaywithjustonesinglekey
strokeoractionof
thecontrols.
The standard display, as defined in the ECDIS
Performance Standards (IMO Resolution A.817(19)
and/or IMO Resolution MSC.232(82)), does not
necessarilydisplayallthechartobjectsnecessaryfor
safe navigation under all circumstances, e.g. spot
soundingsorunderwaterobstructions.
Theseandotherobjectsareall listed or classified
as ‘All
Other Information’ display. Different
manufacturers provide different facilities for
managing the display of chart objects and chart
information.Controlof individual groupsof objects,
e.g. spot soundings, tidal diamonds, place names,
may vary according to each ECDIS manufacturer.
Selectionofcertainlayersofinformationorobjectsfor
display becomes more
obvious with experience but
until then navigators will need to understand the
layer selection requirements for an efficient
navigationaldisplay.Marinersneedalsotoremember
that displaying everything, without seamanlike
consideration,shouldnotbeanoption.
Withsomesystems,itispossibletorunacomplete
safetycheckforanyhazards
alongtheplannedroute
atanytimeduringtherouteplanningprocessandon
completion of planning. However, this functionality
varies among the different makes. Some ECDIS
appear only to undertake route check functions on
larger scale ENCs and therefore alarms might not
activate.Thismaynotbealsoclearly
indicatedonthe
ECDISdisplayscreen.
Mariners should always undertake careful visual
inspectionof theentire planned route using the ‘All
Other’ display mode to confirm that it, and any
deviationsfromit,isclearofdangers.Watchkeeping
Officers should verify that all compulsory
information (base & standard) are selected.
Masters
arerequired to prescribe minimum display category
requirements on the ECDIS for each stage of the
voyage. Usually there is also recommendation (e.g.
basedonTeekayNavigationalHandbook(2017))that
thefollowinginformationareincludedinusercharts
during passage planning stage: watch condition,
positionfixinterval,primaryand
secondaryposition
fixmethods,parallelindexing,maximumspeedbased
on minimum required UKC, echo sounder/printer
activation,abortline/pointofno‐return,NoGoAreas
(anti grounding alarm enable),
contingency/emergency anchorages, VTS reporting
points, special zones (MARPOL, ECA, etc.), any
master’s remarks (any orders, comments, etc.), all
importantnotices/remarks(1hournotice
toER,ERto
be manned, etc.). In addition, ‘chart auto load’ and
‘chartautoscale’aretobeonatallthetimeswhenin
navigation. If two ECDIS are installed, one ECDIS
shouldalwaysbesettothebestscale(1:1).
SCAMIN is an optional attribute by the
chart
producer (defined by IHO S57) that can be used to
label ENC chart features to be suppressed above a
certaindisplayscale.Themainfunction ofSCAMIN
istode‐clutterthechartdisplay,enablingtheuserto
focusonthemostusefulnavigationalinformationfor
the display scale in
use. SCAMIN may affect the
display as it removes certain information from the
displayifbestscalechartisnotbeingusedi.e.safety
criticalinformationmayberemovedfromthedisplay.
A buoy that has the IENC Encoding Guide’s
recommendedSCAMINsettingof10000willonlybe
shownon
the display if the selected display scale is
greaterthan1:10000(Largerscale).
The system auto‐filter means that unless
navigatingonthebestscalechart,OOWwillnotsee
all the information available for display. Therefore,
when zooming out the system will automatically
deselect certain features from display such
as
soundings,lights and topographical detail. The only
way to ensure that the display is not affected by
SCAMIN is to always ensure that the chart is being
used on the best scale. Navigators should always
checkthepassageplansat‘compilationscale’before
useandduringroutemonitoring.
Compilation
scaleisthescaleoftheENCatwhich
the chart data was compiled based on the nature of
the source data. It’s the scale at which the chart
information meets the IHO requirements for chart
accuracy.
Navigators must exercise extreme caution when
using the scale or zoom facility of the
electronic
charts.Itispossibletozoom‐intoascalelargerthan
thatusedinthecompilationofthedatawhichcould
create a false impression about the reliability of the
charted information. Consequently, it could give a
falseimpressionofsafewatersaroundthevessel.
Also,somefeatures
maybenotdisplayedbecause
of the SCAMIN (Scale Minimum) attribute of ENC
objects.Zoomin/outfunctionshouldonlybeusedfor
shortperiodsoftime.IfpossibleSCAMINsettingsto
bekept‘off’duringthepassageplanningstage.
Safety depth (SD) is a value that serves to detect
depthsthat
areadangertonavigation.Adepthequal
toorlessthanthesafetydepthishighlightedonthe
chart in bold type when the display of the spot
sounding is turned on. This alertsthe userto know