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‘No Overlay' Feature

Where there is no equivalent Admiralty paper chart, the UKHO does not have any additional information and the Overlay shows a ‘No Overlay’ feature. This feature is displayed as a grey polygon with a grey hatched fili indicating the area where there is no overlay information.

Additional information, such as iocal T&P NMs, may be available in these areas from other sources. When navigating in these areas, mariners shouid ensure that all appropriate sources of information have been consulted.

Using the Overlay to Navigate

The Admiralty Information Overlay contains additional safety and NM information which is considered navigationally significant and may affect your voyage. This information shouid be referred to when planning your passage and may also be temporarily displayed during route monitoring.

When planning your passage it is normal to review all charts (and therefore ENCs) that are expected to be used on the passage. When these charts are reviewed the Overlay shouid be turned on and any features that could affect the planned route shouid be investigated. Those features that are significant for the planned passage shouid be marked using Mariners Navigational Objects, which can be displayed by the ECDIS when navigating. Sufficient information shouid be attached to the Mariners Navigational Objects to inform the navigator of the action to be taken when they are encountered on passage.

If the ECDIS is capable of displaying the Overlay, Overlay information may temporarily be displayed when navigating. To avoid clutter on the ECDIS display the Over!ay shouid normally be turned off and shouid only be turned on for brief periods when required for reference. Therefore Mariners Navigational Objects shouid be used to draw attention to relevant Overlay features when the Overlay is turned off.

Chapter 10

Admiralty Raster Chart Service (ARCS)

Introduction

ARCS charts are high quality, digital facsimile copies of British Admiralty (BA) paper charts, and share a common numbering system. Chart availability is pubłished in the ‘Catalogue of Admiralty Charts and Pubłications’ (NP131), in the Admiralty Digital Catalogue which can be downloaded from the UKHO website at www.ukho.gov.uk/catalogue, and in Admiralty e-Navigator Planning Station.

Additional charts are announced in Admiralty Notices to Mariners. ARCS charts provide a world-wide electronic chart coverage that can be used within Electronic Chart Display and Information Systems (ECDIS).

This guide is designed to help you gain maximum benefit from using the service, and shouid be used in conjunction with your ECDIS User Manuał

Service Overview

Over 3200 ARCS charts are now available on 11 Raster Chart (RC) CD-ROMs. covering the workfs major trading routes and ports. Each CD-ROM contains an average of 270 charts, but as many as 350 can be stored. Regionally based Chart CD-ROMs RC1 to RC10 contain standard BA nautical charts, while RC11 contains ocean charts at scałes of 1:3,500,000 and smaller. However, please notę that some ocean charts are provided on regional Chart CD-ROMs to provide continuous coverage, instead of RC11.

New Editions and New Charts

New Editions and New Charts for ARCS and BA paper charts are issued simultaneously. They are supplied on each weekly Update CD-ROM until incorporated into their respective ‘Home' CD-ROMs at the next issue. Please notę that New Editions and New Charts replacing charts already licensed, are supplied free of charge until the licence expiry, but will require loading from the Update CD-ROM (in instances where one chart is replaced by morę than one new chart, access to all replacement charts is provided).

Occasionally, it is necessary to issue new charts in advance of their intended datę of vaiidity, for example a change in regulations commencing on a futurę datę. In such cases the current chart will co-exist with the new chart until the datę of implementation, the earlier chart being indicated with a suffix ‘X’. The system will allow access to both charts for the period of over!ap by the issue of new chart permits. At the datę of implementation, the old (‘X’) edition shouid be dełeted from the system.

Licence Period

ARCS is licensed for a period of 12 months. At the start of the licence period users will receive an ARCS Start-Up Pack containing all 11 Raster Chart CD-ROMs, the latest Update CD, a Chart Permit file and a Schedule A from their Admiralty Chart Agent. The Chart Permit file unlocks the charts added to the licence and the Schedule A lists the licensed charts for your records.

During the licence period, ARCS Update CDs will be supplied weekly to enable the licensed charts to be maintained for Notices to Mariners. You will also be provided with all New Editions and replacement charts within your licence. These updates are also avai!able by email and over the internet using the Admiralty Updating Service or Admiralty e-Navigator Planning Station.

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