AIO contains ADMIRALTY paper chart T&P NMs where temporary information is not encoded into the underlying ENC. Each NM carries the same NM number that is used in the Admiralty Notices to Mariners Bulletin.

AIO is designed for the ECDIS user, so T&P NMs that only relate to paper charts, including Port Approach Guides are not included.

AIO also highlights navigationally significant differences between ENCs and ADMIRALTY paper charts,published as ENC P NMs (or EP NMs). It does not contain NAVAREA Warnings or any other information.
The precise requirements for managing temporary and preliminary information will depend on your Flag requirements and those of the Port State that you are visiting. However most consider that T&P information is an essential part of ensuring that the charts in use are up to date. Many ENC producers include T&P information in their ENCs - there is a list in the INFO folder on the AVCS discs and on the UKHO website at


 'Support' tab > 'Download the current status of T&P NMs in ENCs'.

Please be aware that the T&P NMs shown in the Overlay relate specifically to ADMIRALTY paper charts and may not include all T&P NMs issued by the ENC producer. Areas where the UKHO does not publish T&P NMs are highlighted with a ‘No Overlay’ feature. Additional information, such as national T&P NMs, may be available in these areas from other sources and users should ensure that all appropriate sources of information have been consulted.

How T&P information is included in the passage plan depends on your bridge procedures and the requirements of Flag and Port State Control. We recommend that features that are significant to the passage plan should be plotted in ECDIS using Mariner's Information Objects.