VIRTUAL TOWPATH WALKS - photos of locks, bridges etc. Useful for comparing then-and-now.
Grand Union canal(link is external)
Kennet & Avon canal(link is external)
Regents Canal, Rivers Lee and Stort(link is external)
Stratford-upon-Avon canal(link is external)
Wyreley & Essington canal(link is external)
Derby Photos(link is external)
This site has some time-lapsed boating videos which you need to download before viewing. Click on the 'Yes' button after opening the link, enter the site and then select 'Time Lapsed Videos'
Virtual locks
This set of links will show how locks work (with varying degrees of success!)