Nor must it be forgotten, so swift was the subsequent progress both in the range and effectiveness of submarine activity, that this was, at that time, a branch of the service scarcely tried and of unknown possibilities. The submarines used were of a type soon so outclassed as to become almost obsolete, the easiest of prey to net and torpedo, and working at a distance from their bases then unprecedented. Nevertheless, after the Expeditionary Force had been safely transported to France, they were, in the words of Commodore, afterward Vice-Admiral, Roger Keyes, "incessantly employed on the enemy's coast in the Heligoland Bight and elsewhere, and have obtained much valuable information regarding the composition and movement of his patrols. They have occupied his waters and reconnoitred his anchorages, and, while so engaged, have been subjected to skilful and well-executed anti-submarine tactics; hunted for hours at a time by torpedo craft, and attacked by gunfire and torpedoes." That was written on October 17, 1914, when the action, now about to be described, had already made the Bight of Heligoland a familiar term to most people, but without conveying, perhaps, to more than a very few all that it meant from a strategical standpoint. Between three and four hundred miles from the nearest of our naval bases, and from some of the chief of them more than six hundred miles distant, it was in this small area that there was concentrated practically the whole of Germany's naval forces, the {29} Kiel Canal connecting it with the Baltic, rendering these available in either sea. Nor would it be easy to imagine, from the point of view of defense, either a bay of littoral with greater natural advantages. Bounded on the east by the low-lying shores of Schleswig-Holstein, with their fringe of protecting islands, and on the south by the deeply indented coast-line between the Dutch frontier and the mouth of the Kiel Canal, each of the four great estuaries, from west to east, of the Ems, the Jade, the Weser, and the Elbe, had been subdivided by sandbanks into a meshwork of channels than which nothing could have been easier to make impregnable. These were further guarded by the continuation of the scimitar curve of the Frisian Islands, beginning opposite Helder in Holland with the Dutch island of Texel, becoming German in the island of Borkum just beyond the Memmert Sands, opposite the mouth of the Ems, and continued, as a natural screen, in the successive islands of Juist, Nordeney, Baltrum, Langeoog, Spiekeroog, and Wangeroog as far as the entrance of Jade Bay, covering the approach to Wilhelmshaven.