Navigable and for many miles having an accompanying towpath, The Thames Path National Trail takes walkers through some of the most beautiful and peacefull English countryside - then ends up passing right through London. However much of the latter stages of the route is tree-lined and so on at least as far as Battersea from where things do get a bit noisier i.e. the tourist chaos around London Bridge and Tower Bridge.
Generally the towpaths should be useable and passable for both walkers and cyclists however
you can come across sections where the bank has semi-collapsed - this can be a considerable hazard particularly for cyclists. If you see the towpath is overgrown with
high growth both sides
this usually indicates a collapse has occurred - expect to find holes and often deep mud.
There is a speed limit which applies to everyone
using England's canal and river towpaths and that is maximum 4mph. This speed limit includes cyclists who are always required to respect and give way to walkers and who may also need a permit to cycle on some towpaths
. Especially (apart from nearer into London) The Thames Path in many areas is not suitable and not meant to be cycled along. Motorised vehicles are not allowed on the towpaths and trails unless they need access and they have to have
Although the canals are generally not very deep they usually contain a thick layer of mud and also have quite a lot of weed - obviously quite
hazardous for young children in particular should they decide to fall in. Perhaps just as potentially hazardous are the canal locks - they have quite deep
drops when empty or of course contain many feet of water when filled - most locks do not have guard rails or similar. Rivers of course have their own hazards - strong currents, deep mud, lots of weed - care must be taken. Both rivers and canals often have weirs close by some of which can be walked across - this means strong currents and deep water - once again liberties should not be taken.