other insisted that it should be given a trial. The convoy
had one irresistible attraction for the officer which seemed to
counterbalance all the objections which were being urged
against it. Its adoption would mean taking the offensive
against the German submarines. The essential defect of
the patrol system, as it was then conducted, was that it was
primarily a defensive measure. Each destroyer cruised
around in an assigned area, ready to assist vessels in distress,
escort ships through her own "square" and, incidentally,
to attack a submarine when the opportunity was presented.
But the mere fact that a destroyer was patrolling a particular
area meant only, as already explained, that the submarine
had occasionally to sink out of sight until she had passed by.
Consequently the submarine proceeded to operate whenever
a destroyer was not in sight, and this was necessarily most
of the time, for the submarine zone was such a big place and
the Allied destroyer fleet was so pitifully small that it was
impossible to cover it effectively. Under these conditions
there were very few encounters between destroyers and submarines, at least in the waters south and west of Ireland, for
the submarines took all precautions against getting close enough to be sighted by the destroyers.
But the British and French navies were not the only ones which, at this time, were depending upon the patrol as a protection against the subsurface boat. The American navy was committing precisely the same error off our Atlantic coast. As soon as Congress declared war against Germany we expected that at least a few of the U-boats would cross the Atlantic and attack American shipping; indeed, many believed that some had already crossed in anticipation of war; the papers were filled with silly stories about "submarine bases" in Mexican waters, on the New England coast, and elsewhere; submarines were even reported entering Long Island Sound; nets were stretched across the Narrows to keep them out of New York Harbour; and our coasting vessels saw periscopes and the wakes of torpedoes everywhere from Maine to Florida. So prevalent was this apprehension that, in the early days of the war, American destroyers regularly patrolled our coast looking for these far-flung submarines. Yet the idea of seeking them this way was absurd. Even had we known where the submarine was located there would have been little likelihood that we could ever have sighted it, to say nothing of
