Canalmap is a Free online map of the canals and waterways of Britain Showing Bridges, Locks, Water points and other services and official Visitor Moorings.
For those who may be interested, the Canalmap overlay is now running on a Raspberry Pi.
The map is constantly being revised and improved and I don't suppose it will ever be "finished".
Using The Map
You can zoom in and out of the map using a mouse wheel or the + and - buttons at the top left of the map.
The square symbol below the + and - will make the map full screen.
The arrow symbol will, if you have a GPS receiver attached, (most tablets and smart phones) centre your location on the map and follow your movements.
The symbol at the top right of the map will allow you to use different base maps and to switch the canalmap overlay on or off.
The symbol below that will enable the selection of the type of icons displayed.
The map is a work in progress and may be updated/added to often.
For route planning I recommend CanalPlanAC.
For maximum dimensions canaldata.com looks pretty useful.
Tidal Waters. This map is only an approximation for tidal waters and is no substitute for a proper chart.
Canalmap uses some data from Openstreetmap
Canalmap Contains Ordnance Survey Data © Crown copyright and database right 2015
The latest source for the map is HERE