Following Morello's advice, the marksmen were now aiming for the boat itself. The bullets pattered like hail on the water about them. Suddenly there was a ripping sound and a shower of splinters flew about Nat, who was laboring gallantly at the oars.
"Apove der vater line," announced Captain Nelsen calmly. In the glare cast by the light the white wound on the gunwale of the boat could be seen distinctly.
"But it shows that they have our range," commented Nat. "The next one will do more damage."
The boy was right.
After a dozen more bullets had pattered about them, two missiles simultaneously pierced the side of the boat below the water line. The sea began to squirt in in two little fountains. But Captain Nelsen was prepared for just such an emergency. Pulling out his immense red bandanna handkerchief, he tore it into strips and plugged the holes.
A few seconds later the glare died down, and they were safe for the time being. Nat rowed desperately to get out of range before those on board the schooner could light another flare.
Whether he would have succeeded in this purpose, however, is destined not to be known. Hardly had the blue flare died out before the night was illuminated with an even more ghastly radiance. The lightning began a regular witch-dance to the westward of the schooner and the boat. It patterned the night sky like a bit of fine lacework.
It was well that they had that light by which to see and prepare for the peril that now menaced them. As it was, however, Captain Nelsen had barely time to shout a warning before another puff of the same hot wind as had assailed the schooner blew sharply over them. At the same instant Nat, looking up, espied coming toward the boat at a terrific pace what appeared to be a mountainous wall of white water. It roared as it came like a mighty waterfall.
All this, however, they had little time to note before they were in the midst of the vortex of water. By sheer instinct Nat dropped his oars and clung to a thwart as the wave rushed down on them. The next instant he felt him himself borne down by a crushing weight of water. The breath was fairly jammed out of his body, while tons of green water seemed to be above, about, and on every side of him.
At last, sputtering and gasping, he emerged into air again. But things were not as they had been before the passing of the mighty wave. The boat was now full of water to her gunwales and had she not been fitted with air chambers would inevitably have gone to the bottom. Nat was immensely relieved to hear the captain's voice beside him.