Add Motion Blur effects in Photoshop CS6
Motion Blur is a handy tool for creating artistic effects in Photoshop
Duplicate the Background layer (by dragging it onto the ‘Create a new layer’ button at the bottom of the Layers palette) and then Go to Filter>Blur>Motion Blur.
Drag the Distance slider to the right. You can leave the Angle adjustment at its default setting.
Click on the ‘Add a mask’ button at the bottom of the Layers palette. Then press ‘B’ on your keyboard to activate the brush tool and paint the sand back into sharp focus. This way, only the water and clouds are affected by the Motion Blur. Tweak the Curves or Levels if the image needs more contrast after Motion Blur has been added.