In an extremely varied career, he is perhaps best known for his seminal books on angling, particularly salmon and sea trout fishing; however, he was also a noted filmmaker and broadcaster for the BBC.

James retired early to a boat, first on the Essex marshes and then in Devon, whereupon Hugh was sent to the Culford School,[citation needed] in Suffolk.

According to his entry in the Oxford Dictionary of National Biography, Hugh caught his first fish when he was four, learned to shoot when he was six, and was an expert helmsman by the age of fifteen.

After the war he left Doris and in 1950 he married Diana Vaughan, the young editor of Argosy magazine, but on 12 May 1951 Diana was drowned, along with Charles Osborne, Bill Brendon and Sam Lee, in a boating accident off the coast of Achill Island in County Mayo, Ireland, while they were making a film about the local shark hunting industry.

Falkus, a powerful swimmer, took command and ensure other members of the party including his wife were equipped with flotation devices; roping them together into a raft, and then set out for help.

He lived with her at Cragg Cottage, Eskdale, for most of the rest of his life, writing about fishing and natural history and making television films on related subjects.