Green’s Dictionary of Slang

ship (in full sail) n.

a pot of ale.

1857		‘Ducange Anglicus’ Vulgar Tongue.
1859, 1860		Hotten Dict. of Modern Sl. etc.
1864, 1867, 1870		Hotten Sl. Dict.
1873		Sl. Dict.
1928		Bath Chron. 4 Aug. 25/6: An enthusiast arrived [...] to quote: [...] ‘ship in full sail,’ a pot of ale; ‘navigator Scot,’ baked potatoes all hot; ‘Joe Savage,’ a cabbage; ‘bowl the hoop,’ soup; ‘Billy Button,’ mutton.
1935		A.J. Pollock Und. Speaks.
1960		J. Franklyn Dict. of Rhy. Sl. 120/1: ship in full sailA pint of ale [...] The term in its reduced form, a ship, is still in use.
1972		Dodson & Saczek Dict. of Cockney Rhy. Sl.
1981		P. Wright Cockney Dialect and Sl. 103: ships in full sail ‘pint of ale’.
1998		C. Fitzpatrick ‘Gower ’98’ on Sussex University Canoe Club 🌐 So we scooted into Jim Brown, for a ship in full sail and to stuff our Jem Mace with some in the nude.