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 getting near it. We might have learned that a German U-boat was operating off Cape Cod; we might have had the exact latitude and longitude of the location which it was expected that it would reach at a particular moment. At the time the message was sent the submarine might have been lying on the surface ready to attack a passing merchantman, but even under these conditions the destroyer could never have reached her quarry, for as soon as the U-boat saw the enemy approaching it would simply have ducked under the water and remained there in perfect safety. When all danger had passed it would again have bobbed up to the surface as serenely as you please, and gone ahead with its appointed task of sinking merchant ships. One of the astonishing things about this war was that many of the naval officers of all countries did not seem to understand until a very late date that it was utterly futile to send anti-submarine surface craft out into the wide ocean to attack or chase away submarines. The thing to do, of course, was to make the submarines come to the anti-submarine craft and fight in order to get merchantmen.