River Festival

We went to Stratford (on Avon) for a walk this afternoon, and suddenly found ourselves in the midst of a huge celebration down by the river. One of the men explained that it was honouring one of their saints, but I couldn't catch the name. The sounds were tremendous, with chanting, drums and bells chiming.
These men had just lowered an image made of flowers into the river. It looks like Ganesh to me, as we saw many similar when we were travelling in southern India, but it may not be at all. 
The extra is the fun on the river bank. 
Some men wore T-shirts which read "Om sai ram" but I can't find any connection with that and today's date. It may possibly be to do with Hare Krishna and/or Kerala. It was all great fun and a really happy festival with smiling faces everywhere. There were thousands of people and it was really colourful.
See C's blip (Nikonabike) for an idea of what the flower-image was like before it disappeared under the Avon.