August 21, 2017
Admiralty Notices to Mariners (NMs) are designed to help mariners update their Admiralty Standard Nautical Charts (SNCs) and ensure they contain the latest safety critical information.
The NM tracings are a key part of this service as they allow crews to quickly pin-point the position of any updates and accurately apply them to their nautical charts. On 10th July, the UKHO released a new tracing style that will make these updates easier to understand and apply to charts.
How have the latest Notices to Mariners Tracings changed?
The way in which the updates are presented on the tracing itself. For example, all information that needs to be inserted will now be shown in its exact position, rather than appearing in a box and arrowed in. Below are a couple of examples of the principle changes that have been made.
All information that needs to be deleted will be shown with double strike through alongside a deletion symbol. Previously this information may have been boxed or hatched.
Above shows an example of information that needs to be deleted
All information that needs to be inserted will now be shown in its exact position on the tracing in relation to the chart. Previously this information was boxed, with its position shown as a small circle with a dot at the centre.
Above shows an example of information that needs to be inserted
Replace or Amend
Any new features will now be shown in its true position on the tracing and will be accompanied by the words ‘in lieu’. Previously any information that needed to be amended would have featured a double strike though with new information arrowed ‘in lieu’.
Above shows an example of information that needs to be replaced or amended
Any information to be moved will be shown in its new position with an arrow drawn from its existing position.
Above shows an example of information that needs to be moved
To assist and support crews further on understanding these changes you can download the quick-guide-of-new-notices-to-mariners-tracings-notation and an-overview-of-new-notices-to-mariners-tracings-notation document of the latest tracing changes.