Mostly in shot in Manual mode (some in AV) to keep the sensor from being tricked by the foamy white water. I prefer shooting with Landscape Picture Style to give me additional punch and sharpness without having to adjust very much in PP. And most importantly shot at a time when the light was even and soft (unfortunately I wasted a lot of the best light in a bad location so some of these were a little darker than I would have liked.)
Additionally, I used ISO 50 and max ap. to manage the time of the exposures.