that could arise in the danger zone was anticipated and
the officers and the crews were trained to meet it. They
perfected themselves in the signal code ; they learned the
art of making the sudden manœuvres which were instantaneously necessary when a submarine was sighted;
they acquired a mastery in the art of zigzagging; and
they became accustomed to sailing at night without lights.
The crews were put through all the drills which prepared
them to meet such crises as the landing of a torpedo in
their engine-room or the sinking of the ship; and they
were thoroughly schooled in getting all hands safely into
the boats. Possibly an occasional scare on the way over
may have introduced the element of reality into these
exercises ; though no convoys actually met submarines
in the open ocean, the likelihood that they might do so
was never absent, especially after the Germans began
sending out their huge under- water cruisers.
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
