Down the River by Oliver Optic

In the water, struggling for his own or another's life, a man's stock in trade consists mainly of breath. Without that he can't do much, and generally he fails for the want of it; not when life deserts him, but when he might, by an economical use of it, have been able to save himself. I had been in the water enough to learn this lesson, and to be competent to advise all my young friends, in the moment of peril, to refrain from useless and unreasonable struggling, for that wastes the breath, and fritters away the strength.

I held on at the raft till I had recovered my breath, and felt strong enough to make another effort; for I found that my own life and that of my charge were to depend principally on my own exertions. Sim was willing, but he was stupid; and I was afraid that some blunder of his would yet lose me the battle.