I lived in Charing, near Ashford for years and was thinking - I'm sure the Medway doesn't run near there.
Wondering if I jsut hadn't noticed it I thought I would check & found this map.
You could put wheels on the canoe and go down the north downs in it? That said I went sledging on the north downs when I was about 11 and end up with a tree in the eye!!
so do be careful!!
Jon