Introduced by Cliff Michelmore

Canals may be too slow for freight, but is it worth investing public money in them for pleasure boating? Dick Tracey joins the Government adviser on inland waterways John Humphries on a canal cruise to the National Rally of Boats at Lymm in Cheshire. They examine some of the engineering achievements which made British canals famous over a century ago, and debate the case for their upkeep as leisure playgrounds in 1973. Is overcrowding and pollution of our rivers a threat to health, fishing and wildlife? At Streatley, a Thames Conservancy inspector, the head of a boat hire firm, and a yacht club chairman illustrate the growing conflict of interest on the Thames between boat owners, anglers, hikers, campers and naturalists.