Meanwhile ensued a tedious wait. Unable to anchor, since the seas were vicious and breaking, and the holding-ground was bad, No. 21 had to keep her motor running, continuously throttling down, so that her position was practically unaltered. Yet the task of keeping to the channel was one that taxed the helmsman's and the engineer's skill to the uttermost. The latter, unfortunately, was seized with a violent attack of sea-sickness, yet in spite of the nausea, accentuated by the reek of hot oil, he stuck doggedly to his post, knowing full well that any failure on his part to keep the motor running would inevitably result in the boat becoming a total wreck on the Dairymaid Sands, with the possibility of loss of life on the part of the crew. Very slowly the day dawned, the growing light laying bare the dangers that the veil of night had partly hidden. R.A.F. No. 21 was still chugging away in the centre of the channel. Ahead, astern, as far as the eye could see, was a foaming mass of broken water, thundering to leeward upon the flat, sandy beach. Broad on the starboard beam the Bar Buoy, the light of which had ignominiously failed, was plunging in the foaming water. Beyond the buoy the outlines of Old Tom, the detached chalk pinnacle, could be faintly discerned through the mirk. The lofty hills were as if they were not. Hidden in the driving rain, their absence gave the coast-line an unfamiliar aspect. Midway between the edge of the buoyed channel and the sand-dunes lay a long, low grey craft over which the breakers were sweeping continuously. From a light mast two flags streamed out stiffly in the breeze. Being end-on they were unrecognizable until a temporary change in the wind revealed their nationality. The upper one was the Rising Sun of Japan; underneath was the craven Black Cross of Germany. The stranded craft was a surrendered U-boat that had been handed over to Japan, and it was an unfortunate occurrence that on the commencement of her voyage to the Far East the prize showed every sign of slipping through her new owner's fingers. "This is a rummy world," thought Derek. "A few months ago I was doing my level best to strafe these bounders; now I'm doing ditto to assist in the salvage of one of them. But, by Jove! I wouldn't give much for her chance; she's done in, I fancy." Midway between the motor-craft and the U-boat lay the life-boat, buoyantly riding to a long cable. She had approached the stranded vessel as close as she dared, and was even now in danger of bumping her keel on the hard sand. Solidly constructed and well built as she was, she could not afford to risk stranding in the breakers, which would roll her over and over like a barrel. It was almost dead low water, and until the flood had made considerably it was madness for the life-boat to attempt to run alongside the U-boat and take off the crew.