Top to bottom, the Upper and Lower Moriston features less than 2 km of whitewater. But when the Dundreggan dam is releasing, this Scottish classic turns on for lap after lap of stoke. Once you’ve warmed up on the Upper, get ready. The steeper, more committing Lower delivers back-to-back waterfalls stacked into tight basalt gorges. With weekly releases from April to November, keep the boats loaded and the banter fresh.