The first, the Nocturnes, premiered in Paris in 1901 and though it had not made any great impact on the public, it was well-reviewed by musicians including Paul Dukas, Alfred Bruneau and Pierre de Bréville.

[4] He began composing the work while visiting his parents-in-law in Burgundy; by the time it was complete, he had left his wife and was living with Emma Bardac, who was pregnant with Debussy's child.

[4] Debussy retained fond childhood memories of the beauties of the sea but when composing La mer, he rarely visited it, spending most of his time far away from large bodies of water.

In a letter to André Messager, he described the planned sections as "Mère belle aux Îles Sanguinaires", "Jeu de vagues", and "Le vent fait danser la mer".

[18] Trezise writes that "for much of La Mer, Debussy spurns the more obvious devices associated with the sea, wind, and concomitant storm in favour of his own, highly individual vocabulary".

[19] Caroline Potter, in The Cambridge Companion to Debussy, comments that Debussy's depiction of the sea "avoids monotony by using a multitude of water figurations that could be classified as musical onomatopoeia: they evoke the sensation of swaying movement of waves and suggest the pitter-patter of falling droplets of spray" (and so forth), and–significantly–avoid the arpeggiated triads used by Schubert and Wagner to evoke the movement of water.

[21]The author, musicologist and pianist Roy Howat has observed, in his book Debussy in Proportion, that the formal boundaries of La mer correspond exactly to the mathematical ratios called the Golden Section.

[24][n 4] Another Parisian critic, Louis Schneider, wrote, "The audience seemed rather disappointed: they expected the ocean, something big, something colossal, but they were served instead with some agitated water in a saucer".

[25] When the conductor Karl Muck gave the first American performances of La mer in March 1907,[26] the critic Henry Krehbiel wrote: Last night's concert began with a lot of impressionistic daubs of color smeared higgledy-piggledy on a tonal palette, with never a thought of form or purpose except to create new combinations of sounds.

[34] One reason for the negative reception at the Paris premiere may have been public disapproval of Debussy's treatment of his wife,[35] but another was the mediocre performance by the conductor and orchestra.

His biographer Edward Lockspeiser called La mer "the greatest example of an orchestral Impressionist work"[41] and more recently, in The Cambridge Companion to Debussy, Nigel Simeone commented, "It does not seem unduly far-fetched to see a parallel in Monet's seascapes".

[43] The pianist Sviatoslav Richter called La mer "A piece that I rank alongside the St Matthew Passion and the Ring cycle as one of my favourite works".

British composers Frank Merrick and Hope Squire arranged La Mer for piano duet and performed it in 1915 in one of their new music recitals.