The term, the Narrow Sea or the Narrow Seas, was applied at different times or by different writers to very various areas. In its original and more restricted sense it denoted the Straits of Dover; sometimes it signified only the southern sea or the Channel proper; at other times it included also the sea south of the Wash and the Texel; and yet again it was synonymous with the whole of the British seas in which dominion was claimed. In the political poem, The Libelle of Englyshe Polycye, which was written about 1436 with the object of rousing the nation to the paramount duty of “keeping the sea,” the narrow sea is spoken of as lying between Dover and Calais,[10] as it is also in the records of the Privy Council for 1545, which mention the appointment of ships to “kepe the passage of the Narrow Seas.”[11] Later in the same century, and very generally in the seventeenth century, it was used to include the Channel, as when the Earl of Salisbury in 1609 referred to “his Majesties narrow seas between England and France,”[12] and likewise the sea off the Dutch coast; and at this period the Admiralty usually distinguished between the guard of the Narrow Seas and that of the North Sea.
But in other cases, and very commonly in the seventeenth century, the Narrow Sea was equivalent to the marginal sea along the whole coast or to the “British Seas.” Thus in one of James’s proclamations in 1604 for preventing abuses in and about “the narrow seas,” they are referred to as being commonly called the four English Seas, and this was repeated in a proclamation of Charles I. in 1633. So also Lord Chief Justice Hale in his treatise, De Jure Maris, describes the narrow sea, adjoining to the coast of England, as part of the waste and demesnes and dominions of the King of England; and in another work he speaks of the narrow sea lying between us and France and the Netherlands.
After the union of the Crowns the “British Seas” were very often referred to, and there was equal want of definition of their limits as in the case of the Sea of England. The advocates of the English claims to the sovereignty of the sea assigned them a wide but vague extent, while the Dutch argued that the British Sea was the Channel, the Mare Britannicum of Ptolemy and others, the North Sea being distinct and known as Oceanus Germanicus. In many of the diplomatic negotiations that took place on the subject there were heated discussions as to the meaning of the term the “British Seas,” and in point of fact the British representatives, like the Admiralty itself, were unable to define them. The only serious attempt which was made to define the Sea of England or the British Seas in relation to the claim to its sovereignty was made by Selden in 1635. It did not fail on the side of modesty, for according to him the Sea of England was “that which flows between England and the opposite shores and ports.”[13] More particularly in the opening chapter of his second book he describes the British Sea (Oceanus Britannicus) as being divided into four parts according to the four quarters of the world. On the west lay the Vergivian Sea, also called the Deucaledonian Sea where it washes the coasts of Scotland, and in which Ireland is placed; on the east is the German Ocean, so called by Ptolemy because it lies opposite the German shore; on the south, between England and France, is the sea especially noted by Ptolemy as the British Sea, the Mare Britannicum; but in reality all the sea extending along the shores of France through the Bay of Aquitaine (Bay of Biscay) as far as the northern coast of Spain was British. Since the northern and western ocean stretches to a great distance, to America, Iceland, and Greenland, and to parts unknown, it could not “all be called British,” but inasmuch as the King of Great Britain had very large rights in those seas, beyond the extent of the British name, it was not wholly to be left out of account. The indefiniteness of these boundaries to the north and west is obvious, but in a chart which he furnished, and which is reproduced in the frontispiece of this book, he presumably represented what he regarded as the British seas proper; and in several places in his work he expressly declared that the English sea and the English sovereignty of the sea extended to the opposite shores of the Continent.
Throughout almost the whole of the remainder of the century after the appearance of Mare Clausum, Selden’s authority was paramount on all questions relating to the sovereignty of the sea, and his description of the extent of the British seas was very generally adopted, both by writers and by the Government, at least in theory. But it not infrequently happened on particular occasions when a precise definition of their extent was required, that only a vague declaration was forthcoming. Again and again one finds English admirals and naval commanders imploring the Admiralty to tell them the bounds of the British seas, so that needless broils about the salute might be avoided. As a rule, no reply was given to their inquiries; and when it was, it was usually so oracular as to be of little practical advantage. Thus the Earl of Lindsey, when placed in command of the first ship-money fleet, put the question to Secretary Coke, and was told that his Majesty’s seas “are all about his dominions, and to the largest extent of those seas,” and similar explanations were given on other occasions. There is evidence that neither the Admiralty nor the law officers of the crown were able to state what the boundaries of the British seas were, and sometimes the Trinity House was appealed to, with but little better result. In truth, it was part of the national policy to leave their boundaries undetermined. The free navigation of the North Sea and the Channel was of vital importance for many of the states of Europe, and three of them at least—the Netherlands, France, and Spain—had large interests in the fisheries on the British and Irish coasts. If this country had by a formal act of state assigned definite and wide boundaries to the British seas within which sovereignty was claimed, it would have led to frequent and hopeless wars or to constant humiliation. By leaving them vague and ambiguous the pretension to maritime sovereignty could be put forward and used as a political instrument when the navy was strong and occasion offered, and when the navy was weak the pretension might fall into the background without the national honour being unduly tarnished. But on the whole, the claim to the sovereignty of the so-called British seas became an anachronism and was allowed to die out from practical affairs, surviving only in the pages of historians, naval writers, and pamphleteers. During the almost constant naval wars in the eighteenth century a new principle came into being for the delimitation of the neutral waters of a state, the extent of the adjacent open sea that might be appropriated being determined by the range of guns from the shore. All the water within reach of cannon-shot could be protected and commanded by artillery on the land, and thus made susceptible of exclusive and permanent dominion. This principle was accepted very generally by the various maritime Powers as offering a just and equitable means of fixing the limits of their territorial waters, within which the bordering state had exclusive sovereign jurisdiction. It has also been accepted by the great majority of modern publicists, and the phrase of Bynkershoek, “terræ dominium finitur ubi finitur armorum vis,” has become enshrined in the Law of Nations.
Later, and mainly through the action and practice of the United States of America and Great Britain since the end of the eighteenth century, the distance of three miles from shore was more or less formally adopted by most maritime states as equivalent to the range of guns, and as more definitely fixing the limits of their jurisdiction and rights for various purposes, and, in particular, for exclusive fishery. At the time the three-mile limit was introduced, that distance did indeed represent the farthest range of artillery, so that the boundary was the same in each case; and it was sufficient to secure to neutrals that their coasts should not be violated by the operations of belligerents carried on beyond three miles from the shore, while at the same time it furnished a practical measure of the extent of the protection that neutral Powers were bound to afford to the vessels of one belligerent from attacks by the other. But all this is changed. Guns are now able to throw shells to a distance of fifteen miles and more, and the three-mile limit has become quite inadequate to secure the coasts of a neutral from damage from the guns of belligerents engaged in hostilities in the waters near their shores. The argument is not uncommonly used that inasmuch as Great Britain is the predominant maritime Power, it is to her advantage that the territorial waters of all countries should be as narrow as possible. The wider the theatre the better chance for our navy, either in engaging the battle fleets of the enemy or in capturing his shipping. The importance of the change in the conditions referred to above is overlooked. There has been no great maritime war in Europe since the three-mile limit was adopted as the equivalent of the range of guns. If and when another maritime war unfortunately breaks out, it would be absurd to suppose that the neutral Powers within the sphere of possible operations would be content with a three-mile limit to safeguard the security of their coasts. As provided for in the rules drawn up by the Institute of International Law, their duty would be to prohibit all hostilities within such distance of their coasts as would render them secure, and this in turn would involve the immunity from capture within the same space of the merchant vessels of one of the belligerents by the vessels of the other. And thus if this country were engaged in a great maritime war, such as occurred a century or so ago, a very considerable belt of sea on neutral coasts would be closed to the operations of the fleet, and the conditions of naval warfare would be profoundly changed.
With regard to the other questions of sovereignty or exclusive rights in the seas washing the coasts of a country, it is becoming more and more recognised that there is no reason in nature why the boundary for one purpose should be the boundary for all purposes. Just as the three-mile limit is now obsolete in respect to belligerents and neutrals in time of war, so is it inadequate in all cases with regard to the protection and preservation of the sea fisheries. In the concluding chapters of this book it is shown that all recent inquiries by Parliament into the condition of the fisheries, especially of the North Sea, have resulted in proving the inadequacy of the present limit for fishery regulations, and in recommendations that the subject should be dealt with internationally by the various countries concerned.