The Outlaws of Mars by Otis Adelbert Kline

SO FAR as physical comforts went, Jerry and Junia were pleasantly installed on a pile of cushions in the cabin of Padrath's swift little boat. The boatman himself sat in the front of the cabin on a saddlelike seat, manipulating the two driving levers which controlled both the speed and direction of the craft. The corpulent, red-faced officer occupied a cushion across from them, and Neem, the black dalf, snoozed at their feet.

Under any other circumstances it would have been pleasant to glide swiftly and smoothly over the placid waters of the canal, leaving a wake of ripples that sparkled in the mellow light of the farther moon.