Whenever an Allied submarine met its enemy the contest was usually a short one. The issue, one way or the other, was determined in a few minutes. On rare occasions there were attempts to ram; almost invariably, however, it was the torpedo which settled the conflict. If our boat happened to be on the surface when it sighted the German, which, however, was very seldom the case, the first manoeuvre was to dive as quickly and as unostentatiously as possible. If it succeeded in getting under before the U-boat discovered its presence, it then crept up, guided only by the periscope, until it had reached a spot that was within range. The combat, as was the case so frequently in this war, was one-sided. The enemy submarine seldom knew its assailant was anywhere in the neighbourhood; a merchant ship, from its relatively high bridge, could sometimes see the torpedo approach and turn out of its way; but it was almost impossible to see a wake from the low conning-tower or periscope of a submarine, and no one except the observer had a glimpse of the surface. The small size of the submarine was in itself a great protection; we launched many torpedoes, but only occasionally scored a hit. The missile would usually pass a few feet ahead or astern, or would glide over or under the submerged hulk, perhaps a few inches only saving it from destruction. Once an American torpedo hit its enemy squarely on the side but failed to explode! If the torpedo once struck and functioned, however, it was all over in a few seconds. A huge geyser of water would leap into the air; and the submarine would sometimes rise at the same time, or parts of it would fly in a dozen directions; then the waters would gradually subside, leaving a mammoth oil patch, in which two or three members of the crew might be discovered struggling in the waves. Most of the men in the doomed vessel never knew what had struck them.