Green’s Dictionary of Slang

water (usu. as a drink); occas. as v.

1880		D.W. Barrett Life and Work among The Navvies in DSUE (1984).
1912		Sport (Adelaide) 8 June 14/2: They Say [...] Tommy N. has caught a tart, and turned the shicker [...] down. Tom now takes a drop of Fisherman’s Daughter, and doesn’t get John Bull.
1932		‘P.P.’ Rhy. Sl. 15: When a bloke’s got his ‘greengages’ ‘fisherman’s’ ain’t no ‘Robin Hood’.
1934		J. Franklyn This Gutter Life 159: I sees yeh got the fisherman’s daughter laid on an’ all.
1953		J. Franklyn Cockney 293: He may add that he will not get elephant’s trunk– or he may abbreviate to elephant’s – (drunk) on it because it is half fisherman’s daughter (water).
1969		S.T. Kendall Up the Frog 13: D’yer want any fisherman’s daughter wiv yer pimple and blotch.
1971		J. Jones Rhy. Cockney Sl.
1981		P. Wright Cockney Dialect and Sl. 103: fisherman’s daughter ‘water’.
2001		M. Coles Bible in Cockney 17: You’re to cover the whole nanny with tar [...] That should keep the fisherman’s out.
2002		K. Lucas ‘All my life I’ve wanted to be a Barrow Boy’ in Obfuscation News Apr. Issue 20 🌐 The only trouble with an animal is that everyday you have to feed and Fisherman’s Daughter them.