Route planning and overview of electronic chart systems tricky

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One previously recognised problem area is still unresolved. Those who have trained with ECDIS (Electronic Chart Display and Information System) know about the problem that all details are not shown in different scales on electronic charts, but it is still worth making a reminder. Various electronic chart systems are used to different extents, but it is almost only when the ECDIS standard is fulfilled with requirements on training and corrected charts (ENC) that paperless navigation may be carried out. The problem with missing information becomes particularly significant when there is no route planned in the electronic chart system. The safety barrier in ECDIS systems that checks whether the route goes over any grounds does not function. The second safety barrier, checking the correct scale to enable the details necessary for safe navigation, may also be put out of function if an operator zooms out to get an overview. It may be justified, however, to deliberately turn off some alarm functions after a risk assessment by the officer in charge to avoid ”drowning in alarms” while navigating in the archipelago. The following two incidents are examples of the improper use of the systems and poor route planning.
Incident 1
A ship with a draught of 4.9 metres was using a substandard electronic chart at the time of the incident. The navigation officer had previously sailed the route in smaller ships. If he had looked at a paper chart or used the route planning tool in ECDIS with an official electronic navigational chart (ENC), the choice of route would probably have been different.

SLMA TSS 2012-419

Incident 2

The second example is a situation where a navigator stated he remained in the ”zoomed-out” navigational chart to get an overview, resulting in detailed information about the three-metre contour being lost or not seen (position of arrow-head). Had he been observant in any sense, the grounding would have been avoided.

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