The work of the squadron consisted in intercepting and boarding all vessels bound into or out of the northern entrance to the North Sea, and this work could obviously not be carried out in the face of the German submarines without heavy risk to the ships. The danger was greatest during the operation of boarding, as the examining vessel was obliged to stop to lower the boarding-boat. As the number of German submarines increased, the squadron was necessarily withdrawn to positions further removed from the enemy submarine bases, and the Blockade line, after the spring of 1915, ran generally from the Orkneys and Shetlands past the Faroe Islands to Iceland, and when freedom from ice rendered passage round the north of Iceland possible, ships operated in that neighbourhood. A careful organisation of the movements of the ships was necessary to cover such an immense area of the sea, and to provide that all ships should, as far as possible, be intercepted. Even in the case of ships of such large coal endurance as the armed merchant steamers, it was not possible to keep much more than one-half the number in commission on an average on the patrol line at the same time. The remainder were either in port refitting and refueling, or were _en route_ to and from the bases. The distance from the middle of the patrol line to Liverpool was some 600 miles, so that two days were occupied in the passage each way. [Illustration: _Plan N^{o.} 2._ Chart showing in pecked lines the area in which the ships of the 10^{th.} Cruiser Squadron usually worked after about the middle of the year 1915; the positions of the ships being constantly changed. Prior to this the areas were in the vicinity of A.B.C.D.G. ] When going to or from Liverpool the ships had to run the gauntlet of enemy submarines, which were passing down the west coast of the Hebrides and Ireland, and as no destroyers were available with which to screen them against attack, the risk was considerable. They had also to face the constant danger of mine-fields. Several ships of the squadron fell victims to submarines or mines with a resultant heavy loss of life. Whilst the ships were on patrol, the work of the boarding parties was very arduous. The preliminary examination could not be carried out without boarding, and the manner in which the boats of the squadron were handled in the very heavy weather, almost constant in northern latitudes, was a fine tribute to the seamanship of the officers and men. In this boarding work the fishermen of the Newfoundland Royal Naval Reserve, hardy and experienced seamen, rendered most conspicuous service.