I would love to do this!
I was brought up around the canals/rivers/lakes... my best friend lived on a houseboat and we used to knock about on a punt and canoes and I used to walk a Shire Horse along the canal towing a narrow boat for the tourists! lol
It can be quite expensive to hire a narrow boat tho. A couple of mates of mine went on a 'night under canvas' holiday where you literally were given just a sleeping space on the narrow boat, no other facilties ( toilet was a hole at the end of the boat.. !! ) not sure I would want to do that ..but hey ho.
XK.... I guess you mean pushbikes?