He looked at his watch, then gave orders preparatory to another halt, then looked at his watch again. After a minute and a half on converging lines he called a halt. Once more the listeners heard the submarine motors stopping more quickly than before, but now they were near enough to get a fix in spite of the abruptness with which the sound ceased.
The fix showed the submarine now only a thousand yards from both the flagship and the port wing boat. Fraser well knew that as long as the destroyer lay still they could detect the submarine at this range if she tried to move at a speed of more than one knot. Therefore, he took his time planning how to place his depth charge pattern, for, though the stern of each ship was well stocked with these destructive cans, the total area which they could cover with the certainty of a kill was, after all, not large. The maneuver planned to a nicety, he gave the order for the final charge.
“We can cover him this time,” he said.
Jumping to thirty knots, the port wing boat and the flagship rushed in on sharply converging courses till the men on the bridge of each ship watched with their hearts in their mouths the black hulk of the other looming up as if nothing could avert collision. But when they were less than five hundred yards apart, Fraser calmly said, “Right rudder,” and flashed a signal to the other ship, at which both destroyers swerved upon parallel courses just before they reached the spot designated by the last fix.
At that moment Fraser gave the signal to begin the barrage of depth charges. From rack and Y-gun the great cans splashed into the water, three every six seconds from each ship, and then shock after shock seemed to jar the whole ocean. Astern through the flying sheets of spray from the bow could be dimly seen a solid wall of white fountains towering high against the sky. Meanwhile the starboard ship, left behind by the submarine’s dodging to port, raced after the other two with all the speed she had. Overtaking them she laid her pattern down, piecing it on to those already begun by the other two, so that not a square yard of the designated area should escape the force of the high explosive. For half a minute the first two ships let loose this frightful din, twenty charges from each ship; then, as the starboard ship finished her pattern, it ended as suddenly as it had begun, and at a single word from Fraser all three stopped short to listen. Had they got her?
It was at this point that the magnetic detector showed what it could do. This device was able to show the presence of a mass of steel the size of a submarine if it came within a hundred and fifty yards. One man on each ship had been assigned to keep his eye on this and nothing else. As soon as the din had ceased, reports came to the flagship’s bridge that toward the end of the area bombed a small deflection had been seen on the flagship’s detector, and one twice as large on that of the port ship.
“She couldn’t have been beyond the port boat, could she?” asked Fraser.
“No; we shouldn’t have got any deflection at all in that case,” answered Evans.
“Can you trust it not to make deflections out of nothing, or due to the depth charges?”
“No gear is absolutely infallible, but I think you can trust this, especially as the starboard boat got no deflection, and the sub hardly could have got far beyond the port wing boat, in the time she had.”