Ken Ward in the Jungle by Zane Grey — Read

Pepe's long years of _mozo_ work, rowing for tarpon fishermen, now stood the boys in good stead. All the hot hours of the day he bent steadily to the oars. Occasionally they came to rifts, but these were not difficult to pass, being mere swift, shallow channels over sandy bottom. The rocks and the rapids were things of the past.

George lay in a kind of stupor, and Hal lolled in his seat. Ken, however, kept alert, and as the afternoon wore on began to be annoyed at the scarcity of camp-sites.