The email that went round before hand had a comment at the end about watching out for the bad water quality, which one of the newbies didn't understand. So I did my bit for paddler education and explained all about the bubbler and CSO, which I'm sure he appreciated ;)
Apparently though it was really bad on the rainy day itself: there were some hardy folk out there and in particular above Hammersmith Bridge everything you could think of was seen floating by.
However if there is a gap in posts you will know that the worst has happened!