Feb 262010
 

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Your ECDIS may not display significant shoals and may not set grounding alarms automatically because some ENC producers did not understand the importance to safety of a bulletin issued by the International Hydrographic Organisation.

A lucky visit by a maritime delegation to the UK Hydrographic Organisation has sparked a flurry of urgent messages and updates in the electronic chart community after the delegation noticed that a significant shoal was missing from the ENC chart on the screen and no grounding alarm was set on the ECDIS. The was being reviewed prior to issue and the problem was only noticed because the visitors were familiar with the area displayed.

The international Hydrographic Organisation has called for an urgent re-examination of ENC data after discovering that several ENC producer states “may not have fully
appreciated the safety implications behind the advice contained in ENC Encoding Bulletin 27 issued  in April 2009. As a result, ENC producer States may not have taken appropriate action, especially in relation to ENCs that were already published before Encoding Bulletin 27 was issued.

Says an alert issued by the IHO: “Encoding Bulletin 27 alerts ENC producers to the fact that great care must be taken when encoding isolated shoal depths, such as those often marked as “reported” on paper charts, and which represent a hazard to
navigation. Failure to encode these shoal depths, as explained in Encoding Bulletin 27, will result in the depth not being displayed in ECDIS operating in the “standard” or “base” display mode. Most significantly, and not explicitly explained in Encoding Bulletin 27, is that on most ECDIS those same shoal depths will not trigger any automatic grounding alarms in any mode of display.”

IHO’s Directing Committee has written to all 42 states which sell ENCs warning of the potential consequences for safe navigation if ENCs are available for sale that contain data that does not display optimally in ECDIS and ‘strongly encouraged’ then to urgently review their ENCs to ensure that their data was encoded as explained in Encoding Bulletin 27 and to report their findings back to the Directing Committee as soon as possible.

Says IHO: “ It has been confirmed that corrective action is required in a number of
States’ ENCs around the world. The producer States who have responded have indicated that this will be done by urgent re-encoding of the relevant data and the issue of ENC updates in no more than a few weeks.”

In the meantime some ENC producer states have initiated area warnings to alert mariners to the potential problem until all ENCs have been reviewed and updated if necessary.