I had to have an hour or so off writing my dissertation so headed to Rainham. It was back to familiarity here, with unfortunately none of the last couple of week's Western or Glaucous-winged Gulls greeting me. However I quickly clapped eyes on this adult Caspian Gull: -
Metal-ringed, it seems to be the bird that Steve Arlow photographed (admittedly much better than me!) at Pitsea tip, Essex on 4th August 2012 with images reproduced on Birding Frontiers and Steve's own site here.
Loads of other gulls, including many Yellow-legged Gulls and my first juvenile Common Gull of the summer.