It was the result of an error of judgment on the part of Derek Daventry. He had laid off the course of the chart without taking into consideration the leeway made by the slowly-moving boats and the ungainly sea-plane; neither had he made allowance for the deviation of the compass, which happened to be one and a half points on a westerly course; there was also the indraught of the tide, which tended to set a vessel shorewards. All three factors were hard at work during the run through the fog-bank. The first breaker bore down, enveloping the leading boat's bows in a swirling cascade of water. Lifting the stocked anchor from its bed it swept the heavy mass of metal overboard. With a rush and a rattle the cable paid out until the boat brought up with a savage jerk. Simultaneously she swung round broadside on to a particularly fearful-looking breaker. Pouring over the cockpit the water promptly short-circuited the ignition, and the motor stopped dead. Helpless in the trough of the sea, the boat was at the mercy of the next crested wave. "Cut away the sea-plane!" shouted Derek. A hand gave the tautened cable a slash with a knife. Simultaneously the second boat cast off her steadying-line, and the abandoned sea-plane began drifting towards the shore with incredible rapidity. To make matters worse the engineer, under the impression that the next sea would roll the boat completely over, kicked off his sea-boots and plunged overboard. In the grip of the tide he was swept to leeward, and even had he been an exceptionally good swimmer his chances of reaching the shore alive were very remote. A deck-hand, seeing his comrade's predicament, jumped into the sea and struck out to his aid. It was a gallant but unavailing act, although by so doing he additionally hampered the work of rescue. Meanwhile the second boat, ignorant of what had occurred, was making heavy weather in the breakers. She had all her work cut out to keep "end-on" to the hissing, seething masses of water that threatened to overwhelm her. Her coxswain-learner, who had a few months previously been steering a plough on a chalky Wiltshire down, was handling the boat with cool and calculated skill. For want of an engineer Derek tackled the broken-down engine, working in feverish desperation in order to make an effort to save his two men. Plugs were out and replaced in record time, the magneto was wiped and dried, and the cylinders "doped". A couple of determined swings of the cranking-lever and the engine fired, spasmodically at first, then with every indication of "carrying on". "Slip the cable!" shouted Derek.