That area of the sea surrounding the Northern Isles of the Orkney Islands and below the line of the mean high water springs on these Islands bounded as follows: on the north by a straight line extending in an easterly direction from a point at 59° 25'N latitude and 3° 30'W longitude to a point at 59° 25'N latitude and 2° 15'W longitude; then on the east by a straight line extending in a southerly direction from the last mentioned point to a point at 58° 58.4'N latitude and 2° 15'W longitude; then on the south by a straight line extending in a westerly direction from the last mentioned point to Mull Head at 58° 58.4'N latitude and 2° 42.7'W longitude on Deerness Peninsula on the mainland of Orkney and then generally in a westerly, northerly, north westerly and westerly direction along the northern shore of the mainland to Brough Head at 59° 8.2'N latitude and 3° 20.3'W longitude and then by a straight line extending in a westerly direction to a point at 59° 8.2'N latitude and 3° 30'W longitude; then on the west by a straight line extending in a northerly direction from the last mentioned point to the point of beginning at 59° 25'N latitude and 3° 30'W longitude.