The Association would like to inform Members of a situation involving the use of ECDIS in base or standard display modes. The following information was received from the British Chamber of Shipping.

"Mariners are advised to take particular caution with a very small proportion of shoal soundings, especially those marked as "reported" on paper charts. They will not be visible when operating in the base or standard display modes and may not trigger automatic grounding alarms in any display mode, even if their depth is less than the vessel safety depth set in the ECDIS.

This is due to a specific manner of encoding in these particular shoal soundings within S-57. Because of the potential impact on safety of navigation, ENC producing nations are urgently re-examining all their ENCs and taking corrective action where this is necessary. All ENCs produced by UKHO will be corrected over the next few weeks. Where available, information in respect of ENCs produced by other nations included in UKHO's ECDIS and AVCS services will be provided within the readme.txt file of the service CDs.

"An alert has been issued through NAVAREA warnings, which can be seen below."

NAVAREA 1 – Warning 037/10

Mariners are advised that ECDIS may not display some isolated shoal depths when operating in "base or standard display" mode. Route planning and monitoring alarms for these shoal depths may not always be activated. To ensure safe navigation and to confirm that a planned route is clear of such dangers, mariners should visually inspect the planned route and any deviations from it using ECDIS configured to display "all data".

The automated voyage planning check function should not be solely relied upon. The International Hydrographic Organization (IHO) is leading technical action to resolve this matter. Further information will be made available through Notices to Mariners."

Source of information:

Chamber of Shipping

http://www.british-shipping.org