Back to Sid's filmography: The Deepest Hole in the World is a film of a 1970 expedition by a strong team of northern cavers which had the objective of pushing the bottom of the Réseau Pierre de St. Martin. Cavers featured in the film include Dave Brook, Alan Brook, Dave Yeandle, John Donovan, Steve Calvert, and the legendary French explorer - Max Cosyns. It was commissioned by BBC Manchester, and was first broadcast in June 1973 on BBC One.