Thomas Dunhill’s ‘Sea-Music’ is just the sort of article that needs contextualising. Although what he says is largely still of interest and relevance, it may seem that he is exploring blind alleys. The reader must realise that it was written in 1917 during the darkest days of the First World War. Nowadays, the ‘patriotism’ in some of the text would be anathema to more liberal minds. And the Royal Navy, although still the fourth most potent force in the world, no longer ‘rules the waves.’ Other nations may claim to ‘have possessed pre-eminently the qualities which go to the writing of music of the sea’ including those that look towards the blue Mediterranean. On the other hand, all except the most unhistorical mind can see where he is coming from.
There are basically two approaches to writing sea-music. The first is to create a musical picture of the sea itself. The means to achieve this are manifold, but usually involve some carefully chosen atmospherics designed to show the ocean in all its moods. Mendelssohn certainly achieves this with his two overtures noted by Dunhill below. Debussy has written what is probably the ultimate sea-music in his justifiably famous La Mer. Here, he has used the tools of musical impressionism and pointillism. Dunhill does not seem to be impressed by this Frenchman’s music. Other composers have juxtaposed styles such as Frank Bridge in his Suite: The Sea. Here, themes are more important than effect, but Bridge as not been slow to paint a musical picture where appropriate.
The second approach is to depict humankind’s interaction with the sea. This would cover the multitude of works that sing praise of sailors and their doughty deeds, such as Stanford’s The Revenge, Vaughan William’s Sea Symphony and John Ireland’s song ‘Sea Fever’. Allied to this is the utilisation of sea shanties and other nautical songs, as Mackenzie did in his Britannia Overture. Here it is the recollection of the words that largely create their effect. These works may or may not present sea-mood music.
Thomas Dunhill wrote this essay before Arnold Bax premiered his ultimate sea-scape Tintagel in 1921, Benjamin Dale penned his magnificent tone poem The Flowing Tide (c.1938) and clearly many years prior to William Alwyn’s The Magic Island (1952), which must surely be one of the most impressive pieces of musical sea-painting in the catalogue.
I have included minor edits to the text.
Thomas Dunhill: Sea-Music, Monthly Musical Record July 2 1917
Sea-Music is of many kinds. Just as the sea itself is ever varying in colour, revealing its changeful character to us in blue exuberance or grey gloom, in quiet immensity or madly foaming anger, so the music it inspires cannot be placed all into one category.
Most fine sea-music, however, gives us in some measure the spirit of adventure, for the glamour of romance is almost inseparable from our thoughts or the waters that cover the earth, and the riving lives of those who ‘go down to the sea in ships.’ Mendelssohn’s ‘Hebrides’ and ‘Meerestille’ (Calm Sea and Prosperous Voyage) overtures  have long been accepted as types of such music, though they strike us rather as the impressions of a landsman visitor than as the natural outpourings of a man with the blood of a sea-cradled race in his veins.
Of sea influences of a wilder and more virile kind many instances will immediately spring to mind. Everybody will recall the vivid sea-painting in Wagner’s ‘Flying Dutchman’,  and the less primitive and more subtly expressed music which accompanies Isolde’s journey to Cornwall- the song of the steersman and the hearty cries of the sailors as the ship approaches its destination.  This is music as full of poetry as it is of sea-salt, exactly fitting the environment, and as bracing and exciting as the ocean breeze itself.
There is also wide scope for the musician in the mystic, the dainty Faerie element, which Shakespeare has expressed do completely in The Tempest and elsewhere, in words which run themselves are almost music. This element, of which the lines:
Since once I sat upon a promontory,
And heard a mermaid, on a dolphin’s back,
Uttering such dulcet and harmonious breath,
That the rude sea grew civil at her song.
And certain stars shot madly in their spheres,
To hear the sea-maid’s music,’ 
And the equally musical
‘Full fathom five my father lies;
Of his bones are coral made,’ 
are perfect types, has perhaps been more aptly realized by musicians in their instrumental music than in their vocal settings.
I think we may claim that British composers have possessed pre-eminently the qualities which go to the writing of music of the sea; and as befits an island nation whose sea-power has always been an inspiration as well as a boast, our music has seldom been so good as when it has dealt, either directly or indirectly with the waves which encompass our shores, and the exploits of the mariners who have made our country famous.
Britain may also boast of a vast store of sea folk-music. Many of the Chanteys, or scraps of songs trolled by sailors when at work, still survive. A very interesting collection of these, all authentic and characteristic, has recently been given to us in a volume, edited and furnished with accompaniments by Mr Cecil Sharp, and published by Schott and Co. 
More than two centuries ago Henry Purcell showed us that he understood the free and open-hearted character of sea-music, if not quite all of its magic. His sailor chorus and dance in ‘Dido and Aeneas’  are perfect examples of such art, so British in lilt that their association with the sea-dogs of ancient Troy is almost too patently anachronistic. The songs of Dibdin  and his school, more limited and more local in their scope, portraying the jollity and adventure of the sailor type, rather than the direct influences of the sea, may also be regarded as sea-music of national value.
In these more modern days we may well boast of such a work as Mackenzie’s ‘Britannia’ overture,  which may be regarded as an enshrinement of the Dibdin character in developed music of artistic achievement, for it displays a real, if rather deliberate, sense of breezy sailor humour, and is, moreover, particularly British in its appeal.
Few modern composers have felt the call of the sea more strongly than Sir Charles [Villiers] Stanford. His picturesque ‘Revenge’  is a little masterpiece, which will always remain representative. We know how highly it was rated by Tennyson himself, and poets are notoriously difficult to satisfy with the settings composers make of their works. In this case it is difficult to see how the heroism of the exploit and the pride of British seamanship could have been better expressed in music. Stanford’s art covers a wide range. He gives us many aspects of the sea, and his storm is as convincing as his calm. The same qualities are evident in his ‘Songs of the Sea’ and ‘Songs of the Fleet’,  musical settings which never fail to thrill us and make our pulses beat faster whenever we hear them.
 Felix Mendelssohn’s Hebrides Overture, also known as the Fingal’s Cave Overture was written in 1830 and subsequently revised in 1832. It was first performed in London on 14 May 1832, conducted by Thomas Attwood. The music was inspired by a walking trip to the Western Highlands of Scotland made by Mendelssohn and his friend Karl Klingemann during 1829. The other overture that Dunhill refers to is ‘Meeresstille und glückliche Fahrt’ (Calm Sea and Prosperous Voyage), op.27. This was written in 1832 and was first heard in Leipzig three years later, conducted by the composer. The literary background to the work is two short poems by Goethe: The Calmness of the Sea and A Prosperous Voyage. Edward Elgar quoted a theme from this overture in the 13th variation of his Enigma Variations.
 Thomas Dunhill is referring to the dramatic sea music presented in the overture of Richard Wagner’s opera The Flying Dutchman (1843)
 I understand that Dunhill is alluding to the solo sung by the Steersman in the Act I, Scene I of Tristan and Isolde where the he sings ‘Westwards the gaze wanders; eastwards skims the ship.’
 William Shakespeare: A Midsummer Night’s Dream Act II Scene I
 William Shakespeare: The Tempest Act I Scene II
 Sharp, Cecil J., English Folk-Chanteys (London: Simpkin, Marshall, Hamilton, Kent; Schott; Taunton: Barnicott & Pearce, 1914).
 Henry Purcell (1659-95). The opera Dido and Aeneas was [probably] premiered in 1689 at a boarding school for girls in Chelsea. It is a ‘grand opera’ in the sense that there are no speaking parts. Dunhill is likely referring to the song, ‘Come away, fellow sailors’ from Act III.
 Charles Dibdin (1745-1814) was an assistant in a music shop, a novelist, a singer-actor and composer who specialised in dramatic works. His reputation now rests on his ‘sea-songs’ with the best-known being ‘Tom Bowling.
 Sir Alexander Mackenzie’s Britannia: Overture was first performed in 1894. It became popular at the Proms, being performed at that venue 48 times. The overture makes use of the tunes ‘Rule Britannia’, ‘Jack the Lad’ and three nautical themes devised by the composer.
 Charles Villiers Stanford’s The Revenge: A Battle of the Fleet was first heard in 1886 at the Leeds Musical Festival. John Porte (Sir Charles V. Stanford, London 1922) writes that ‘the spirit of Alfred, Lord Tennyson’s poem gave [Stanford] one of his natural elements, the atmosphere of the sea, in which some of his finest works were to be cast’. This once popular work had ‘page after page…full of fire and salt-sea vigour and strength.’ The music is more a story of the sea, than a depiction of its moods.
 Charles Villiers Stanford’s Songs of the Sea and Songs of the Fleet are both powerful and lyrical choral works setting poems by Henry Newbolt. The former was premiered during the 1904 Leeds Festival and the latter at the same venue on 1910. They have maintained a toehold in the repertoire, both recorded and concert, until the present time.