steering raft

For a hundred yards the river moved straight, then curved hard to the left around a small hill where Brian quickly found that a log raft is not the same as a boat.
  The current was not fast — as he had guessed earlier it was about the speed of a person walking — but it was steady and strong. The logs were heavy and once they were moving in a direction they were hard to turn.
  As a matter of fact, Brian thought, watching the bank at the end of the curve come at him, they were impossible to turn.
  The river curved left and the raft went straight, cut across the curve, and jammed into the bank.
  The jar of the sudden stop, even moving slowly, rocked the raft and Derek rolled against the lashings and almost fell in.
  Brian leaped forward on the raft, fell on Derek and held him while the raft lurched, slid sideways, and settled against the bank, where it stuck in the dirt and brush on the edge of the river.
  One hundred yards and they were stopped.
  Brian slid off the raft — waist deep in the water — pushed it sideways back out into the current, climbed back on and sat for half a minute while the river curved back around to the right and the raft jammed into the left bank.
  Another fifty yards. One hundred and fifty yards and they were stuck twice.
  Brian swore.
  “I’m going to have to improve this or we’ll be a month on this river.”
  He worked the raft into the middle again and it started to move.
  This time, as they came into a shallow curve and the raft started to move straight, he waited until the raft was close to the shore and used the pole to jam into the bottom and fend off.
  He still shot wide on the turn, but they didn’t jam into the bank and by the fifth curve he had found a way to use the crude paddle to steer the raft.
  He would come in close to the shore on the inside of a curve, then as soon as the raft was around it he paddled the stern over and aimed it down the center of the river, and fought to keep it in the middle.
  They still did not always stay in the center of the best-moving current, but as the afternoon wore on Brian found that by frantically paddling through each curve he kept the raft moving almost at the speed of the current and away from any brush or snags on the sides of the river.
  It worked, but the river curved almost constantly, moving through small swamps and beneath overhanging trees so thick it seemed to be a jungle, and he was constantly fighting the raft.
  Inside of three hours he felt his back and arms aching, and knew that if he didn’t stop to rest a bit now and then he would never be able to make it.