ships were the easiest of all to put down, as it is doubtful if their fatalistic officers troubled to keep the watertight doors closed. It must be remembered that there is all the difference in the world between a practice and a war attack. The war attack is usually unexpected, and is done under conditions of light and weather which make things chancy, to say the least of it. In a practice attack an officer can afterwards usually plot on the chart for you every movement his boat and the enemy made, and give reasons for all orders he gave. After a war attack he would probably only be able to remember clearly such things as the periscope hoisting gear giving trouble and the hydroplane men appearing to be unaccountably deaf. I have mixed up several boats' attacks in the following description, and it would not be far wrong as an account of more. II The mist closed in in swirling clouds that came along the calm water in lines a few hundred yards apart. One moment through the periscope the captain of the L-boat could see across the yellow-green sea a band of fog crossing his bows--the next, he could see nothing but the ripples that spread and vanished astern a few feet from the top prism of the instrument. It had been a poor visibility day since dawn, and now it looked like being thick weather till dark. He called to the first lieutenant and gave an order. The hydroplane wheels whirred and the boat tilted up and climbed to the accompaniment of sighs and roars, as a couple of external tanks were partly blown. The captain looked down as he climbed the conning-tower ladder: "Slow ahead, port motor--put a charge on starboard--stop blowing." He threw back the lid and met the clammy touch of wet fog on his face. The boat was moving slowly east through a calm sea with only her conning-tower and guns above water, while a white line of foam running forward traced where her deck superstructure ran a few inches below the surface. If she had been on patrol anywhere but to the west of the Vyl Lightship the captain would have taken her to seventy feet and kept a hydrophone watch, but that billet is one that marks the end of a German swept channel, and he wanted to watch from above for the first sign of the fog clearing. He sat on the conning-tower lip, his sea-booted legs resting on the third ladder-rung, and his head twisting this way and that as he stared at the white wall of mist that was so close to him. He had sat there barely a minute, and the booming roar of the big charging engine had just begun sounding up the conning-tower when he slid forward and stood on the ladder with his head and shoulders only exposed; he leaned out to starboard trying to catch again the faint note of a syren that he had felt rather than heard through the note of his own engine. Then something showed dark through the fog, a grey blur with a line of foam below, and the L-boat's lid clanged down, and through her hull rang the startling, insistent blare of the electric alarm.