As the darkness increased the cold strengthened and a little bitter wind began to moan through the scanty rigging. Men stamped their feet and swung their arms to increase the circulation in numbed limbs, and every now and then during the next three hours one member of the watch on deck would disappear for a few minutes down the galley hatchway to drink a cup of hot cocoa, which, so far, the cook had succeeded in keeping warm on the ill-natured petrol stove.

At 9 p.m. the first watch was over and half-frozen men climbed stiffly down the iron ladder into the tiny fo'c'sle, where the heat and fugg of oil stoves caused their thawing limbs to throb painfully. The starboard watch, fresh from the heat of the tiny cabin, whose four hours on deck now commenced, were shivering in the icy wind and showers of spray.

Glancing at the dimly lit chart on the small table cunningly fitted into the front of the wheel-house, the commander noted the approximate position of the ship in the 140,000 square miles of sea and snow around, and then turning to the coxswain, whose "trick" it was at the wheel, he gave the necessary orders for the course and speed. The duty of this vessel was to patrol certain approaches to the great harbour on which the flotilla was based until relieved at daybreak by another unit, and, as merchant ships had many times been attacked in these waters, a sharp look-out was necessary. To carry this out effectively in the darkness and driving snow was a task calling for all the qualities of dogged endurance inherent in the British sailor.

For over two hours nothing was seen or heard except the moaning of the wind and the lash of the sea, but shortly after midnight one of the look-outs reported the sound of engines away to the starboard.

The M.L.'s propellers were stopped and the watch on deck listened intently. The splash of the sea and the many noises of a rolling ship drowned any other sound there might have been, and the patrol was then continued. Less than half-an-hour later, however, the clank! clank! clank! of engines again became suddenly audible, and the vessel was turned in the direction of the sound.

The engines were put to full speed ahead, and as each comber struck the bows the little ship trembled from stem to stern, and clouds of icy spray swept high over the mast. The big steel hull of some man-o'-war or merchantman might suddenly loom up out of the darkness so close ahead that no skill could avoid a collision, and the eyes of all aboard were gazing alertly into the blackness of the night.

Five minutes' dash through the blinding, stinging spray and the engines were once more shut off to listen. The curious clanking noise had, however, ceased, and although hydrophones were used to again locate the sound, there was no result, only the ceaseless wash of the sea and the low moaning of the wind. Another mile or so of pounding through the waves, followed by an interval of listening, brought the same discouraging result, and the slow, monotonous routine of patrol was continued.

The stinging frost of the night became the numbing cold of early morning, and the long hours in the snow and icy spray had left their mark on all. Limbs were stiff and sore. The edges of wet and half-frozen sleeves rasped swollen wrists. Faces smarted and eyes ached, but little was said in the way of complaint, for men grow hard on northern seas or else succumb to the hardships.

When the first dim light of a winter dawn broke reluctantly over the grey tumbling sea and whirling snow another night patrol was over, and the cheering thought came to all that soon the welcome warmth and shelter of club and recreation room would embrace them for the brief hours of daylight, while others kept watch upon the seas.

It had been snowing hard for the past twenty-four hours, but as the light of a new day strengthened it eased somewhat, and away to the westward the blue outline of the land became visible. The fitful wind of the night rose to a stiff breeze, but no one paid much attention to the increasing volume of bitter spray which swept the deck as the grey-green rollers put on their white caps of foam, for the ship was heading towards the harbour and their vigil was over until darkness again closed down.