The title is a corruption of the French phrase "ça ne fait rien", meaning "it doesn't matter".
Wilfrid Brambell, who stars in this movie as the Grandfather, played Paul McCartney's grandfather in Quatre Garçons dans le vent (1964). McCartney included a song entitled "San Ferry Anne" on his 1976 album "Wings At The Speed Of Sound".
The two babies on board the ferry were the real-life twins of Bob and Anne Kellett.
Ron Moody refused to do the scene where he and Grandad rescue the tent from the sticky mud in Calais Harbour. Bob Kellett stood in for Moody himself in long shot.
Lynne Carol's debut.