“Hold on!” commanded Whistler Morgan. “No use losing our heads over this.” “If one of those bombs lands near us we’ll likely lose more than our heads,” grumbled Torry. “Wait! If we run like a bunch of scared rabbits, we are likely to run right into danger rather than away from it.” “Those horns down there say ‘Find a cellar!’” whispered Frenchy. “Oi, oi!” added Ikey. “There ain’t no cellars up here on this hill yet.” “Keep cool,” repeated Whistler. The other boys were used to listening to him, and to following his advice. He was a cautious as well as a courageous lad, and his chums were usually safe in following Philip Morgan’s lead. These four boys, all hailing from the New England coast town of Seacove, had begun their first “hitch,” as an enlistment is called, in the United States Navy as apprentice seamen, several months before America got into the Great War, and some months before the oldest of the four was eighteen. They had now spent more than a year and a half in the service, and their experiences had been many and varied. After their initial training at Saugarack, the big Naval training camp, the four chums, with others of their friends and camp associates, had been sent aboard the torpedo boat destroyer, _Colodia_, one of the newest, largest, and fastest of her type in the United States Navy. The _Colodia’s_ first two cruises were full of excitement and adventure for the four Navy Boys, especially for Philip Morgan; for he fell overboard from the destroyer and was picked up by the German submarine U-812, and his experiences thereon and escape therefrom, are narrated in the first volume of this series, entitled: “Navy Boys After the Submarines; Or, Protecting the Giant Convoy.” The second of the series, “Navy Boys Chasing a Sea Raider; or Landing a Million Dollar Prize,” relates the experiences of these four friends on a longer and even more adventurous cruise of the _Colodia_. Under the command of Ensign MacMasters, the Navy Boys as members of a prize crew, took the captured _Graf von Posen_ into Norfolk; and their experiences on the captured raider made a dramatic and exciting story of the day-by-day work of the boys of the Navy. Through their kind friend Mr. Alonzo Minnette, who was holding a volunteer position at Washington in the Navy Department, the four chums obtained a chance to cruise with the superdreadnaught _Kennebunk_, a brand new and one of the largest of the modern American fighting machines launched during the first months of the war. The _Colodia_ having gone across the Atlantic while the boys were with the captured raider, they with Ensign MacMasters were very glad to join the crew of the huge superdreadnaught in the interim.