"Right," nodded Jack Benson. "Had the crew been needed on deck I would have ordered them to remain. As I did not so order they have gone below, where they are out of the way until wanted. A craft that fights always on the surface of the water should have some men of the crew always on deck. But here on a submarine the men would be in the way, and we want a clear range of view all over the deck, and seaward, in order that we may see everything that it is possible to see. Mr. Darrin, Mr. Dalzell and Mr. Farley will remain on deck with me. The other young gentlemen will go below to study the workings of the engines under Ensign Hastings." Though it was a true pleasure trip for all six of the midshipmen, it was one of hard, brisk instruction all the time. "Here, you see," explained Lieutenant Jack, leading his trio just forward of the conning tower, "we have a deck wheel for use when needed. Mr. Somers, give up the wheel." "Aye, aye, sir," and Ensign Eph, who had been sitting at the tower wheel since the start, moved away and came on deck. "Mr. Darrin, take the wheel," directed Benson. "Are you familiar with the Bay?" "Not sufficiently, sir, to be a pilot." "Then I will give you your directions from time to time. How does this craft mind her wheel?" "With the lightest touch, sir, that I ever saw in a wheel." "The builders of the 'Dodger' have been working to make the action of the steering wheel progressively lighter with each boat that they have built. Men on a submarine craft must have the steadiest nerves at all times, and steady nerves do not go hand in hand with muscle fatigue." Lieutenant Jack walked to the entrance to the conning tower. "Mallock!" he called down to one of the crew. "Aye, aye, sir." "My compliments to Mr. Hastings, and ask him to crowd the speed of the boat gradually." "Aye, aye, sir." The "Dodger" had been moving down the bay at a ten-knot pace. Suddenly she gave a jump that caused Midshipman Dave Darrin to wonder. Then the submarine settled down to a rushing sixteen-knot gait." "I didn't know, sir," ventured Farley, "that submarines could go quite so fast." "The old types didn't," Lieutenant Jack answered. "However, on the surface a capable submarine must be able to show a good deal of speed." "For getting away, sir?" "Oh, no. Naturally, when a submarine is pursued she can drop under the surface and leave no trail. But suppose a single submarine to be guarding a harbor, unaided by other fighting craft. A twenty-or twenty-two knot battleship is discovered, trying to make the harbor. Even if the battleship steams away the submarine should be capable of following. The engines of the 'Dodger,' in favorable weather, can drive her at twenty-six knots on the surface." "She's as fast as a torpedo-boat destroyer, then, sir," hazarded Dan.