In the first place, the ridiculously wide claims made, on behalf of certain States, by mediaeval jurists were cut down by Grotius to so much water as can be controlled from the land.

The Grotian formula was then worked out by Bynkershoek with reference to the range of cannon; and, finally, this somewhat variable test was before the end of the eighteenth century, as we may see from the judgments of Lord Stowell, superseded by the hard-and-fast rule of the three-mile limit, which has since received ample recognition in treaties, legislation, and judicial decisions.
The subordinate question, also touched upon by the Admiral, of the character to be attributed to bays, the entrance to which exceeds six miles in breadth, presents more difficulty than that relating to strictly coastal waters.

I will only say that the Privy Council, in _The Direct U.S.Cable Co._ v.

_Anglo-American Telegraph Co._ (L.R.2 App.
Ca.

394), carefully avoided giving an opinion as to the international law applicable to such bays, but decided the case before them, which had arisen with reference to the Bay of Conception, in Newfoundland, on the narrow ground that, as a British Court, they were bound by certain assertions of jurisdiction made in British Acts of Parliament.
The three-mile distance has, no doubt, become inadequate in consequence of the increased range of modern cannon, but no other can be substituted for it without express agreement of the Powers.