Notices to Mariners contain important navigational information. This includes chart updates, changes in buoyage warning of activities such as dredging.

Notices to Mariners are issued by several organisations, including the UK Hydrographic Office (UKHO), Trinity House and local harbour authorities. You can often find Local Notices to Mariners online, and many harbour authorities provide email updates you can subscribe to.

Chart updates and corrections

ADMIRALTY Small Craft Chart Service, a division of the UK Hydrographic Office, provides regular Notices to Mariners for keeping Small Craft Charts up to date. You can find information on the ADIMRALTY Small Craft Charts web page.

Imray has a similar corrections service on its website.

The UK Hydrographic Office (UKHO) publishes radio navigation warnings for NAVAREA 1 and the UK coast on the ADMIRALTY website. Many of these warnings are temporary, but others can remain in force for several weeks. These might then be superseded by Notices to Mariners.

Links to Notices to Mariners can also be found in the RYA SafeTrx app.

RYA SafeTrx provides all recreational boat users, including dinghy cruisers, PWC users, RIB users, canoers, kayakers, wind and kite surfers, and smaller boat users, with an easily accessible and simple to use means to inform HM Coastguard of their trip plans and dynamic location in the event of distress.

Available for Android and iOS, the RYA SafeTrx app is freely available to anyone who wants to be safer afloat. It is free to download and there is no charge to use it.