I'm sorry to say the noisy person was one of our party. This weekend was an annual event for a group of members. I think the chap on the SCOD doesn't get out much and was a bit squiffy. We'll remind those on trips in the future to be more respectful of other people on the river.
Incidentally I got some great video footage of a couple of Deben Seals, the most rare species.

http://www.youtube.com/watch?v=5biReIeZ1Qc