Full details of this year's event here:
https://www.waterways.org.uk/events_festivals/canalway_cavalcade_2014/canalway_cavalcade_2014
Here's where it is:
http://maps.google.co.uk/maps?hl=en&ie=UTF8&ll=51.521315,-0.182251&spn=0.002523,0.006968&t=h&z=18