Head out
The right posture not only helps avoid a sore back, it also means better control of the raft by the team as a whole ― especially important when you start plunging through rapids.
1 Sit. Perch on one of the raft’s side tubes; tuck your feet into the raft’s straps or floor pockets, if available, or under the thwarts (the tubes that cross the raft).
2 Grip the paddle. Put the hand that’s toward the center of the raft securely over the T-grip at the top of the paddle, and keep it there at all times (so you don’t thwack your raftmates). Put the other hand near the blade.