"Keep your eyes and ears wide open all the time; remember what you are told and you'll soon catch on," Witt told them.

Shortly before noon Lieutenant McClure, commander of the Dewey, a youthful-looking chap who, they learned later, had not been long out of Annapolis, came aboard. It was soon evident that there was something doing, for in a few minutes the propeller blades began to churn the water, and the exhaust of the engines fluttered at the port-holes. The tow lines ashore were cast off and then very gracefully and almost noiselessly the Dewey began slipping away from its dock. The head of the vessel swung around and pointed out the harbor.

"We're off, boy!" exclaimed Jack to his chum. They were, indeed. The boys were standing in front of the conning tower and, because it was their first submarine voyage and they had yet to acquire their sea legs, they kept firm hold on the wire railing that ran the length of the deck on either side of the vessel. Commander McClure and Executive Officer Binns were up on the deck steering station behind a sheath of white canvas directing the movement of the ship.

"This is what I call great!" laughed Ted as the Dewey began to gather speed and moved out into the bay.

Looking seaward the boys beheld the prow of the submarine splitting the water clean as a knife, the spray dashing in great white sheets over the anchor chains. From aft came the steady chug-chug of the engines' exhaust, to be drowned out at intervals as the swell of water surged over the port-holes. They seemed to be afloat on a narrow raft propelled swiftly through the water by some strong and unseen power.

"I say, old boy, this beats drilling out on the campus at Brighton with the school battalion, eh? what?" exclaimed Jack.

Ted was doing a clog dance on the deck. "I'm just as happy as I can be," was his gleeful comment.

Very shortly the lighthouse that stood on the cape's end marking the harbor entrance had been passed and the Dewey was out on the open sea. Before the boys stretched water—-endless water as far as the eye carried—-to the far thin line where sky and water met. They were lost in contemplation of the wonderful view. But their reveries were suddenly disturbed by a sharp command from Executive Officer Binns:

"All hands below—-we are going to submerge!"

The Dewey was going to dive!