Z?
"...in 1867, after the triumphant return of the Vogelstruis from Venderbight, that 'zee' entered the popular usage. Euphoria! The Difficulty with the Bandages had been resolved. Disfigured and unbreathing friends and relatives boarded the steamers for the tomb-colonies in their hundreds. Box-rooms were empty again. Grave-yards were quiet. And sailors were the heroes of the hour.
Or, as they quickly became known, zailors. The 'zee-zongs' of Mahogany Hall may be credited for the change, especially 'The Fluke and the Fancy Mare' and 'Eat Our Hearts, My Darling' (which latter this author finds, to this very day, infuriatingly 'catchy'). They were popular at the docks, and no wonder! considering the heights to which they praised the sea-venturers! Steamer-crews adopted the habit as a means to differentiate themselves from their surface cousins. 'Zailors' disdained the gaudy blue of sky and sea and praised the subtleties and silence of life below. It has been claimed that the 'z' resonates more powerfully than the 's' in an underground space, though I remain sceptical.
Seas may alter: human nature does not. As it became fashionable to 'zpeak' of 'zteamers', 'ztowaways' and even 'zhips', seamen disdained the appropriation of their argot. They identified over-use of the 'z' as a landlubber's mark. They reserved the 'z' for 'zee', for 'zailor' and perhaps for 'zong'. (And 'zubmarine', though many zailors consider this a dubious and even impious innovation.) They sneered at the swells who affected the 'zpeech'. Yet their own rules remain frustratingly inconsistent. Is zee-bat a pretension or the correct term? Does a zailor refuse to drink sea-water or zee-water? Accounts vary.
This alone is 'zertain': the zailors defend their prerogative to 'z' or not to 'z' with ferocity. Correct a zailor's usage, and suffer a scowl. Refuse a zailor's own correction, and suffer indignities amounting almost to an ambush!"
- P.F. Fulchard, 'Engaging Customs of the Underclasses', 1878