Baselines and bay closing lines

What is it:

The Territorial Sea (Baselines) Order 2014 establishes the baselines from which the breadth of the territorial sea adjacent to the United Kingdom, the Channel Islands and the Isle of Man is measured in accordance with the United Nations Convention on the Law of the Sea.

The baseline is generally the low-water line around the coast, including the coast of all islands.

Links to Scotland's Marine Atlas:

Chapter 1: Introduction

Data originators:

United Kingdom Hydrographic Office (UKHO)

This information page is part of the theme:

Limits and Boundaries

More Information:

Between Cape Wrath and Laggan a straight baseline system is established in accordance with Article 7 of the Convention; this is defined by a series of straight lines joining specified points lying on the low-water line generally on the seaward side of the islands lying off the coast. Elsewhere, where there is a bay, a line not exceeding 24 nautical miles in length is drawn across the bay and will constitute the baseline.

The limits of the territorial sea derived from these baselines are shown on Admiralty Charts published by the UK Hydrographic Office. Also see the 12 nautical mile limit data layer in NMPi.

This page was last modified on :

Thursday, September 28, 2017 - 07:50

Map Type	Click title for metadata and licence information	Date of data	View Map
Map Layers (NMPi)	Baselines and closing bays - Internal waters adjacent to Scotland	2022-10-31	Access this map on NMPi

Type	Link Title	External Link
Legislation, Web link	The Territorial Sea (Baselines) Order 2014	www.legislation.gov.uk