Pretty much continuous grade 2 with some 3. Keep your eyes out for possible tree/fence portages. Hop out at the A470 bridge as the difficulty ups a little and it's worth inspecting the next 500m for trees. Down to the viaduct there's some slides, a slot then a sweet double drop into a slot rapid into a clean 4ft drop. Get out at the viaduct as there's sumps and nastiness if you choose to continue.
Putin · Takeout
Takeout at the viaduct just after the A470 roadbridge (just south of Ffestiniog). A footpath river left leads back to the road. To reach the put-in, head upstream along the road on river right to Cwm Farm.
Rainchasers is best experienced as an app.