Working the Thames Mark Arden and Steve Frost travel from the source of the River Thames (a small hollow in a field in Gloucestershire) along its course to the vast expanse of the Thames Estuary in this highly entertaining Discovery Channel series. Along the way they uncover the working history of the river and meet the men and women who work on the Thames today - river police, ferrymen, lock keepers, dredgers and port pilots who reveal what they do and how their jobs have changed over the years. In each episode Mark and Steve enlist the help of the river workers to help them re-enact a number of river related tasks. One such task involves them sailing a barge down the Thames under 15 bridges - something that hasn't been done for many years. Other tasks involve punting a cargo of beer across the river to a pub near Oxford, having a go at dredging, piling and salvaging on the river, uncovering the last remaining cargo carried in Docklands and hitching a ride out to the Estuary on a huge container ship