RTB (Reclaim the Beach) who have occasional parties on the beaches of the Thames. Next one is planned for the night of July13th on the beach by Royal Festival Hall and apparently these are quite something. Check out www.swarming.org.uk
Low tide is at 11.20pm and I was thinking that it would be adventurous to turn up with a few RIBs around low tide just for fun. Initial thoughts would be to launch from the Isle of Dogs sometime after 10pm and be back on the slipway for midnight.