Good beginner's or play run through little sandstone gorges.
There is easy access to the river from Sorn, Catrine, Auchincruive, Ayr, but the best whitewater is between the villages of Mauchline and Stair. Putin at the old road bridge between Mauchline and Catrine, turning west off the A76 just before it crosses the river. Takeout at the bridge in Stair. If paddling from alternative access points, watch out for a few tricky weirs: one in Catrine, and another by the university in Ayr.
Rainchasers is best experienced as an app.