Notice on categorisation of waters in the UK regions

UK Maritime and Coastguard Agency issued a Merchant Shipping Notice regarding categorisation of waters.

This notice was published on 22 April 2024.

1. Introduction

1.1 The Annex to this Merchant Shipping Notice sets out the categorisations that apply to waters in the United Kingdom. These categorisations are given statutory force by way of Regulation 3(2)(a) of the Merchant Shipping (Categorisation of Waters) Regulations 1992.

2. Definitions of Categorised Waters

2.1 Category A: Narrow rivers and canals where the depth of water is generally less than 1.5 metres.
2.2 Category B: Wider rivers and canals where the depth of water is generally 1.5 metres or more and where the significant wave height could not be expected to exceed 0.6 metres at any time.
2.3 Category C: Tidal rivers and estuaries and large, deep lakes and lochs where the significant wave height could not be expected to exceed 1.2 metres at any time.
2.4 Category D: Tidal rivers and estuaries where the significant wave height could not be expected to exceed 2.0 metres at any time.

3. Application

3.1 These categorisations apply specifically to any vessel certified to operate in waters which are not regarded as “sea” for the purposes of regulations made, or treated as made, under Section 85 of the Merchant Shipping Act.
3.2 Under the Merchant Shipping (Prevention of Oil Pollution) Regulations 2019 it should be noted that “sea” includes any estuaries or arms of the sea.
3.3 These categorisations should not be confused with sea areas for Passenger Ships as designated in the Merchant Shipping (Passenger Ships on Domestic Voyages) Regulations 2000.
3.4 The categorisations shown in the Annex apply at all times of the year unless otherwise indicated. “Summer” means the months of April to October, inclusive, and “winter” means the months of November to March, inclusive.

The Annex offers comprehensive details on the categorization of various regions and locations in Northern Ireland, England, Wales, Scotland, and the East of England, distinguishing between coastal and non-coastal areas.


All regulations can be found at legislation.gov.uk


For more information, please see the documents below (available only to subscribers):


Categorisation of Waters

Annex 1