Just a quick word of praise for Nick's Canal Route Planner — CanalPlanAC — an interactive guide to the inland waterways of Europe. It plans journeys, calculates the length (distance, number of locks, time taken etc) of your trip.
I'm sure he won't mind me saying that it's a bit rough and ready at the moment - but for me it supplies a need and does its basic job really well. If you log in properly you can amend the information if you believe it's wrong and tailor it to your needs. Give it a try and tell Nick you value it!