The convoy commander left his port with sealed orders, which he was instructed not to open until he was a hundred miles at sea. These orders, when the seal was broken, gave him the rendezvous assigned by Captain Long of the convoy board in London. The great chart in the convoy room at the Admiralty indicated the point to which the convoy was to proceed and at which it would be met by the destroyer escorts and taken through the danger zone. This particular New York convoy commander was now perhaps instructed to cross the thirtieth meridian at the fifty-second parallel of latitude, where he would be met by his escort. He laid his course for that point and regulated his speed so as to reach it at the appointed time. But he well knew that these instructions were only temporary. The precise point to which he would finally be directed to sail depended upon the movement and location of the German submarines at the time of his arrival. If the enemy became particularly active in the region of this tentative rendezvous, then, as the convoy approached it, a wireless from London would instruct the commander to steer abruptly to another point, perhaps a hundred miles to north or south. "Getting your convoy" was a searching test of destroyer seamanship, particularly in heavy or thick weather. It was not the simplest thing to navigate a group of destroyers through the tempestuous waters of the North Atlantic, with no other objective than the junction point of a certain meridian and parallel, and reach the designated spot at a certain hour. Such a feat demanded navigation ability of a high order; and the skill which our American naval officers displayed in this direction aroused great admiration, especially on the part of the merchant skippers; in particular it aroused the astonishment of the average doughboy. Many destroyer escorts that went out to meet an incoming convoy also took out one which was westward bound. A few mishaps in the course of the war, such as the sinking of the _Justicia_, which was sailing from Europe to America, created the false notion that outward-bound convoys were not escorted. It was just as desirable, of course, to escort the ships going out as it was to escort those which were coming in. The mere fact that the inbound ships carried troops and supplies gave stronger reasons, from the humane standpoint, for heavier escorts, but not from the standpoint of the general war situation. The Germans were not sinking our ships because they were carrying men and supplies; they were sinking them simply because they were ships. They were not seeking to destroy American troops and munitions exclusively; they were seeking to destroy tonnage. They were aiming to reduce the world's supply of ships to such a point that the Allies would be compelled to abandon the conflict for lack of communications. It was therefore necessary that they should sink the empty ships, which were going out, as well as the crowded and loaded ships which were coming in.