define Western Europe... The UK should allow boating whenever you have time. Norway's Norway, but at some point it will probably be too cold. This leaves the Alps, which will also get a case of winter and thus insufficient water. Southwest Germany and Northwest Switzerland, however, might offer a lot of small creeks that part of the year.
Contact the guys at Canadian Canoe Shop in Huningue, France. I don't know 'em well, but from what I understand, they might be a very good address for that part of the world...