I think you'll find it was the Classic Sailing Club - an interesting concept for those not familiar with it, and one which I'm sure will be (and deserves to be) successful. Certainly its fleet is growing.
I saw them rafted as I went down river on Saturday - if I'm not mistaken a clutch of them were on a single buoy (glad it wasn't mine). Their programme also says they were visiting Ramsholt at the weekend.
I don't think that the organisers can fairly be held responsible after the event for the antisocial behaviour of adults. They might be the right people to speak to at the time to curb said behaviour of course.
http://www.classicsailingclub.com/