He let himself sink, but he was out of breath.

He gasped and inhaled the water, and then, for dear life's sake, he swam to keep his head above it.
The water had cooled his excitement; a feeling of utter helplessness and misery came over him.

So strong was his pity for the little sad-eyed child that he was almost willing to die in seeking her; but all hope of finding was forsaking him.

He still swam in the direction in which he thought the child drifted as she rose and sank.

It did not occur to him to be surprised that she had drifted so far until he realized that he was out of hearing of the sounds from the shore.