3.8.13 Temporary and Preliminary (t&p) Notices

Caution must be exercised when navigating solely with ECDIS as some ENC or RNC data may not take account of temporary or preliminary notices.

Temporary and preliminary noticesare not handled consistently by all ENC producers atpresent. Some producers, like the United Kingdom Hydrographic Office (UKHO), incorporate the T&P notices into the ENCs and theirupdates, whilst others ignore T&Ps completely. The Navigation Officer must check the ECDIScharts to verify whether T&P corrections have been included in the weekly updates.

The UKHO use ‘Admiralty Information Overlay’ to incorporate T&P notices within its ENCs. This tool allows the notices to be displayed as an overlay to the ENC in the Admiralty Vector Chart Service (AVCS), thus assisting the navigator in readily identifying the location and content of a notice during passage planning and the voyage itself.

When using charts produced by other sources, notices may be absent. These must be inserted manually as ‘Mariners Objects’. The NavigationOfficer must monitor T&P notices closely so that once they are withdrawn they are alsoremoved from the ECDIS charts onboard.

3.8.14 Navigational Warnings

Navigational warnings transmitted by satellite communications (for example Sat-C telex), NAVTEX receiver and radio-broadcasted warnings are by nature more short term and urgent than temporary or preliminary notices. Navigators using paper charts as a primary means of navigation will normally plot urgent warnings by pencil on the paper chart itself to ensure that there is clear record and other navigators can clearly see any new plotted dangers in relation to the position of the ship.

Navigators using ECDIS must be aware of the ability to plot new dangers on electronic charts through the use of the Marine Information Objects (MIO) capability. The purpose of the MIO is to highlight navigation warning information on the electronic chart. NAVTEX warnings may be displayed automatically if the NAVTEX is integrated into the ECDIS system.

3.8.15 Admiralty Digital Catalogue

The Utility CD supplied with the chart software should include the Admiralty Digital Catalogue.This catalogue is updated on a weekly basis and allows theNavigation Officer to view the permitted chart coverage and to prepare a basket file forrequesting any additional ENCs required for a particular voyage.

3.8.16 Cancelled Charts

Similar to the paper chart system, new editions of electronic charts are issued on a regular basis. These new editions are supplied on the weekly update CD and should be downloaded as part of the weekly update procedures. Every three months, the suppliers issue new base CDs. Cancelled charts are usually deleted automatically by the system when installing the new base CDs.

3.8.17 Inspections

A provision of a chart system is a high cost item and it is therefore essential that it is maintained correctly.

The monthly chart correction record form NAV13 (ECDIS)is to be completed by the Masteron completion of the weekly chart corrections as notified in the “Weekly Notices to Mariners”.The Master should view the ENC properties on all ECDIS units to ensure that the chartcorrection upload has been carried out correctly. Verification of the correction procedure shouldinclude Navigation Warnings and T&P notices.

Visiting Superintendents and 3^rd party inspectorsmay also check that the ECDIS has been correctly updated.