Weekly Edition 52 of 2012

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Section VI - Radio Signals
Updates to all the Radio Signals are given in Section VI. When a chart-updating notice is issued for information that is also
included within the Radio Signals, the appropriate volume reference number is quoted, followed in parentheses by the
number of the Weekly Edition containing (in Section VI) the corresponding update to the service details. The updates in
Section VI should be cut out and pasted into the appropriate volumes.
Section VII - Miscellaneous Publications
Updates to the following selected miscellaneous Nautical Publications are contained in Section VII.
NP100 The Mariner’s Handbook
NP133A Paper Chart Maintenance Record
NP231 Admiralty Guide to the Practical Use of ENCs
NP294 How to Keep your Admiralty Products Up-to-date
NP136 Ocean Passages for the World
NP350(1) Admiralty Distance Tables – Atlantic Ocean
NP350(3) Admiralty Distance Tables – Pacific Ocean
NP350(2) Admiralty Distance Tables – Indian Ocean
NP735 IALA Maritime Buoyage System
NP5011 Symbols and Abbreviations used on Admiralty Paper Charts
NP5012 Admiralty Guide to ENC Symbols used in ECDIS
All Tides Publications
Nautical Almanac Publications, including Sight Reduction Tables.
Further Guidance
The Mariner’s Handbook (NP100) gives a fuller explanation of the limitations of charts and details of the UKHO policy for
the promulgation and selection of navigationally significant information for charts. Details of chart updating methods can be
found in “How to Keep Your Admiralty Products Up-to-date” (NP294). All users are advised to study these publications.
CAUTIONARY NOTES
Updating
Updating information is published by Weekly Notices to Mariners supplemented by navigational warnings for items of
immediate importance. It should be borne in mind that they may be based on reports which cannot always be verified before
promulgation, and that it is sometimes necessary to be selective and promulgate only the more important items to avoid
overloading users; the remainder being included in revised editions of the charts and publications concerned.
Laws and Regulations
While, in the interests of the safety of shipping, the UKHO makes every endeavour to include in its publications details of the
laws and regulations of all countries appertaining to navigation, it must be clearly understood:-
(a) that no liability whatsoever can be accepted for failure to publish details of any particular law or regulation, and
(b) that publication of the details of a law or regulation is solely for the safety and convenience of shipping and implies no
recognition of the international validity of the law or regulation.
Reliance on Charts and Associated Publications
While every effort is made to ensure the accuracy of the information on Admiralty charts and within nautical publications, it
should be appreciated that it may not always be complete and up-to-date. The mariner must be the final judge of the reliance
he can place on the information given, bearing in mind his particular circumstances, local pilotage guidance and the judicious
use of available aids to navigation.
Charts
Charts should be used with prudence: there are areas where the source data are old, incomplete or of poor quality. The
mariner should use the largest scale appropriate for his particular purpose; apart from being the most detailed, the larger
scales are usually updated first. When extensive new information (such as a new hydrographic survey) is received, some
months may elapse before it can be fully incorporated in published charts. On small scale charts of ocean areas where
hydrographic information is, in many cases, still sparse, charted shoals may be in error as regards position, least depth and
extent. Undiscovered dangers may exist, particularly away from well-established routes.
Satellite-Derived Positions and Chart Accuracy
Mariners must not assume that charts which are referred to WGS84 Datum, or those for which shifts to WGS84 Datum are
provided, have been surveyed to modern standards of accuracy. On some charts, owing to the age and quality of the source
information, some of the charted detail may not be positioned accurately. In such cases mariners are advised to exercise
particular caution when navigating in the vicinity of dangers, even when using an electronic positioning system such as GPS.
For further details, see The Mariner’s Handbook (NP100). This applies to both paper and digital (Admiralty Raster Chart
Service and ENC) versions of charts.
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