Good introduction to moving water for beginners which finishes with a flourish through Jim's bridge.
Putin · Takeout
Putin by parking along the road near Plas-y-Brenin near Capel Curig and walk the boats down a footpath to the end of the lake. The takeout is down the A5 towards Betws-y-Coed, take a small track opposite Siabod Cafe to reach Jim's bridge.
Rainchasers is best experienced as an app.