In an interview with Higher & Higher magazine, Justin Hayward stated the following factors led to the choice of the album's name:

1) The album is filled with references to water and ocean;

2) Someone once asked them where their band was from, England or America, and they decided that an appropriate answer would be somewhere in between (on the sea, or "sur la mer");

3) The name was cinched when they viewed the 1955 painting "Le Fort D'Antibes" by Nicolas De Stael and they decided to use that painting for the album's cover.

Justin has also related the following story in several interviews as to how the album title was selected: When the band got together to make the album, someone asked: "Where shall we begin?" Someone replied, "How about 'on the C'?" (referring to the note middle C on the piano).