We were actually there on Saturday! But yes, as you said I did not see that many boater as I expected! here you can see a picture showing Richmond Lock! it was empty! only we were there and that's it!
Medway the same (tidal). A few more boats than usual, but not busy by any means. Perhaps it was the ordnance explosion on Saturday that was putting people off?!!
Won't be long before everyone complains that the summer weather is cr*p and they can't go out etc etc.....