We used this guide this summer and managed to cycle 330kms along the canal. The book was indispensable! Full of really useful information, also lets you know when to cross to the other side of the canal/river. I would not have attempted such a journey without the book. There was just one omission that I noted, the fact that there is a campsite in Pontivy, just by the canal. Also there should be a warning to cyclists about the poor quality of the track through Finistere. In some places the signage wasn't good, but if the guide was followed you shouldn't get lost.