As the clouds rose higher the sea began to look black. Although they knew what caused this the boys could not keep from feeling a little anxious, especially when the waves commenced to splash them with scud, as they struck the bow of the dipping submarine and broke.
They were really glad, therefore, when the captain ordered them to go below, as it was necessary to make preparations against foul weather. For some time afterwards the little boat labored heavily, until Ballyhoo began to feel the first signs of uneasiness in the pit of his stomach.
All of them felt relieved when they discovered that they were commencing to sink. The water tanks were being filled rapidly, and before long they realized that in truth they had vanished from the surface of the sea.
How calm it seemed down there, with the engines once more taking up their regular pulsations. The boys glued their eyes to the thick plate-glass observation bull’s-eyes, but all they could see when the searchlight was turned on was rushing green water all around them.
Doubtless the storm raged above as the squall spread over the sea, but safe in the stanch little submarine, far beneath the troubled surface, they knew nothing of it. By degrees the three chums became more used to their strange surroundings. The experience of novelty began to wear away. When one becomes accustomed to anything it no longer has the power to excite wonder, and give the same kind of thrill.
Later on they could sleep calmly when lying at the bottom of the sea, even though the manufactured air did seem queer, and breathing not as comfortable as under ordinary conditions, with the pure article to inhale.
Hours passed during which they continued to forge ahead. Oscar figured that they were making something like eight knots an hour while pushing through the depths.
Then came the time when they arose to take an observation through the periscope. The boys, of course, had to be allowed a chance to see, of which they hastened to avail themselves eagerly.
Never would they forget that first experience at looking through the periscope of a submarine far out at sea. The still heaving waters, running far away to the horizon, looked startling to their unaccustomed eyes. It seemed as though they might be lying on the edge of the world itself, and looking over a vast undulating plain.
When the captain judged that it would be safe to come up, as the storm had passed, and the sea was no longer rough, he gave the order.