The Balvaig is a fairly short river on the eastern edge of the Trossachs. The river is a perfect place for canoeing, as it meanders between Loch Voil and Loch Lubnaig.
In normal conditions, it is a quite straightforward grade I paddle, however it has been said that it has "Grade 5 trees" meaning that there are a lot of hanging branches to avoid, possible fallen trees, and you need to be able to manouevre your canoe competently in a flowing river. As long as you are aware of this, you should have no problems.
The surrounding scenery is fantastic, and you can paddle along gently in your canoe whilst looking at the hills around you. At the end, Loch Lubnaig is a beautiful place, and if you wish to extend your canoe trip you can paddle down the loch.