The gauge-needle quivered and began to rise. At eight feet the Captain stepped back, and, taking the periscope training-handles, began to look into the rubber-padded eye-piece, "Check at twenty feet," he said. "Take the angle off now, coxswain." "Twenty feet, sir, horizontal." The coxswain sat on a low heavy music-stool facing another white-faced diving-gauge, his big brass hydroplane wheel moving a turn or two each way under his hand. "Pump on Z internal--_don't_ start till I tell you." The Captain was watching the hydroplane helm indicators beside him, which showed, by the amount of "rise" helm they were carrying, that the boat had a touch of negative buoyancy. "All ready the pump, sir!" "Start the pump--keep her _up_, coxswain." "Coming up, sir--horizontal, sir." "Stop the pump--close main line--close Z internal." On an even keel the E boat ploughed along--her periscope top four feet above the surface, and the periscope-wake bubbling and foaming on the perfectly smooth sea. The watcher in the following destroyer saw the wake die down till it was a barely visible ripple, as--her trim correct--the Captain eased the boat's speed down to less than two knots. Then the shining periscope began to disappear, slowly reducing in height as the planes took the boat down for her deep hull test. Inside her hull there was silence except for an occasional whisper from one seated civilian to his neighbour. The gauge-needles crept slowly round, and as the depth increased the little spot of daylight thrown by the periscope eye-piece on to the pump-starter abreast of it changed from yellow to green of ever-darkening shades till the last link with the sun above them died away. At ninety feet the Captain spoke again, and the hydroplane-wheels spun as her downward way was checked. "Keep her at that," he said. "Mr Ramage, will you send your men round now? We'll mark leaks before we go further."