Facts and figures about Scotland’s seas
Table 1 - Coastline length
At LW mark *
At HW mark *
18,002 kms
18,672 kms
Source: * Scottish Government - created from OS Boundary Line 2007 and OS Mastermap:
coastline length at minimum scale 1:10,000.
Table 2 - Islands
Inhabited**
118
Uninhabited
in excess of 800
Source: **General Register Office for Scotland based on 2010 postcode data.
Table 3 - Scottish sea areas
Description
Area (kms2)
(approx.)
1
2
3
4
5
6
7
8
9
HW mark to territorial sea baseline (Internal Waters)***
Territorial sea baseline to 3 n miles (Water Framework
Directive limit) ***
Area of sea within WFD limit (internal waters & territorial
waters) (1 + 2)
Territorial sea baseline to 12 n miles (Territorial Waters)***
HW mark to Territorial Sea limit (12 n miles) = Territorial
Waters (1+4)
Territorial sea outside WFD (5 – 3)
3 n mile to EEZ limit (EEZ outside WFD) (9-3)
12 n mile limit to EEZ limit *** (9-5)
Total sea area inside EEZ limit (EEZ waters)
34,920
13,790
48,710
55,484
90,404
41,694
413,553
371,859
462,263
Source: *** High water mark from OS Boundary Line 2013. Straight baselines, closing bays
and 12nm limits courtesy of UKHO, accurate as of April 2014. Internal waters estimated by
joining straight baselines and closing bays to low water mark which as derived from OS
Boundary Line 2007, except for area around Shetland, Orkney and Stornoway, which was
derived from OS MasterMap. All area calculations on Albers Equal Area Conic projection
using transformation EPSG 1311 (WGS84 to ED50).
Table 4 - UK sea area
Description
Area (km2)
Approx. %
Total UK sea area to EEZ limit
Scottish seas
English seas
Welsh seas
Northern Ireland seas
Guernsey seas
Jersey seas
Isle of Man seas
Scotland land area (to mean low water)
743,965
462,263
229,966
30,754
6,717
7,342
2,965
3,957
80,060
100%
62%
31%
4%
1%
1%
½%
½%
Sea area : land area ratio
5.85 : 1
Table 5 – Scottish Marine Regions
Region
Area (km2)
Distance along MHWS (km)*
Solway
3,724
774
Clyde
4,279
1,251
Argyll
12,045
2,907
Outer Hebrides
20,849
3,900
West Highlands
10,421
3,642
North Coast
2,443
542
Orkney Islands
9,256
1,224
Shetland Isles
12,310
2,373
Moray Firth
5,876
981
North East
3,153
306
Forth and Tay
4,487
772
(Rockall)**
1,561
Total
90,404
18,672
*This includes skerries, islets etc
**Rockall has 12nm limit but is not included within SMRs
Area and distances calculated on Europe Albers Equal Area Conic projection (ESRI:102013)
using transformations EPSG:1311 (Rockall) and EPSG:1315 (SMRs), and rounded to zero
decimal places.
Notes
 The baseline (from which the limits of the Territorial Sea are measured) will move
depending on the latest surveys of the low water (LW) mark. LW is generally the
datum for baselines except where straight baselines (established in legislation) or
bay closing lines are used. The areas defined as “bays” vary over time due to
improvements in surveys and GIS software.
 The new Exclusive Economic Zone (EEZ), declared in March 2014, established a
new boundary that generally follows the existing continental shelf limits (except in
the area beyond 200 miles). This gives a slightly reduced sea area compared
with the area within the previous fishery limits.
 The area of sea will vary depending on the resolution of the coastline used in
calculations. A higher resolution coastline introduces more variations – indents or
extrusions - which are smoothed out when using a more generalized coast line.
When measuring Scotland’s sea area, a higher resolution coastline introduces
more small islands which has the effect of increasing coastline length but
reducing the sea area.
May 2014
Updated May 2015 to add Table 5