These vessels were driven by twin screws connected to twin engines of about 500 h.p. They possessed, in addition, an auxiliary petrol engine of about 60 h.p. for compressing the air required to start the main engines, for working the fire and bilge pumps, and for driving a dynamo to recharge the electric storage batteries. The triple tanks carried over 3000 gallons of petrol, and the consumption, when travelling at full speed, was a gallon a minute. Many were fitted with wireless, and all of them had on board the most approved pattern of hydrophone, with which to listen below the surface for the movements of hostile submarines. They had electric light in the cabins and for navigation, fighting and mast-head signalling purposes. A moderately powerful searchlight, fitted with a Morse signalling shutter, was also part of their equipment. These little miniature warships possessed a small wardroom and sleeping cabin for the officers, a galley with petrol range for cooking, an engine-room, magazine for the ammunition, chart-room, and ample forecastle accommodation for the crew of nine men. All parts of the ship were connected with the bridge by speaking-tubes and electric bells, and the aft deck accommodated a steel life-boat. The duties of these craft varied considerably. For over three years they maintained a constant patrol in the North Sea, Atlantic, English Channel, Irish Sea, Mediterranean, Adriatic, Suez Canal, Straits of Gibraltar, and in West Indian waters. Only one who knows by experience can fully appreciate what work in these northern seas, with their winter snows and Arctic winds, and their chilly summer fogs, really means to a mere thirty tons of nautical humanity in as many square leagues of storm-swept sea infested with mines and hostile submarines. But when this book has been finished the reader will be in a position to judge for himself. The losses of motor launches were not heavy considering the dangerous nature of their cargoes (3000 gallons of petrol within a few feet of 1500 lb. of high explosive in a wooden hull) and the duties they were called upon to perform in all weathers short of heavy gales. Several were blown up with terrible results to those aboard. Others caught fire and were burned--allowing only just sufficient time to sink the explosives aboard. A few were smashed to pieces on exposed coasts after struggling for hours amid heavy seas. One struck a mine off Ostend. Another was destroyed by shell-fire in the Mediterranean, and the part they played in the raids on Zeebrugge and Ostend, in which two were lost and a V.C. gained, is now world famous. COASTAL MOTOR BOATS