Use of the waterwheel sequence on a cube that is already completely solved as 3-color will misplace two edge facelets, the following example shows how to fix them. The first 9 moves are the waterwheel sequence, move 10 turns the cube to make the setup for Sequence 3C-E2 which fixes the yellow facelet on the top face and the red facelet on the front face (moves 11-15). The corners are then solved with half-twists (16-18) and the cube is ready for the final step of solving the 6-color edges.