The towpath can be very colourful, and whilst many of the people who do attend actually are interested in the rowing, not every one is.
Those with the stripey blazers of many colours are perhaps those who are into the rowing ....
A difference since my last visit, couldn't help noticing many more hospitality marquees along the towpath, almost the full length of the course (it's over a mile in length). Corporate hospitality has made it big time here.