Every new aspect of the submarine advancement had to be thought out and met, and the variations were most noticeable, but during the last few months of the war considerable attention had to be concentrated on the areas of the Azores, the north, south, east, and west of Ireland, the Bristol Channel, and the approaches to the English Channel in the west. But by the spring of 1918 the crews of German submarines had become distinctly inferior. Their commanding officers were often young and raw, there was a great dearth of trained engineer officers and experienced petty officers, and this was shown in frequent engine-room breakdowns. So many submarines had failed to return home, and others reported such hairbreadth escapes, that the inferior crews became nervous and were not sorry to be taken prisoners. The fact was that not only were expert, highly skilled officers hard to find, but the hands he was compelled to go to sea with were no longer chosen by the captain; he had to accept whatever recruits were drafted to his craft. Of the best _personnel_ that remained many had lost their nerve and had a very real dread of mines, depth charges, and decoy ships. The institution of our convoy system and of Q-ships as part of the convoy did not add to the pleasures of the U-boat officers. It is true that the often excellent shooting of the submarines was due to the fact that their gun-layers were generally selected from the High Sea Fleet, but as against this many of our Q-ship expert gunners were out of the Grand Fleet. It is true that the cruiser submarines with their two 5·9-inch guns, plus torpedoes, were formidable foes even for the most heavily armed decoy, but as against this they took a long time to dive, and thus represented a better target.