Green’s Dictionary of Slang

a shave; also as v.

1910		Eve. Teleg. (Dundee) 3 Aug. 4/1: He will rub his chin and exclaim, 'I've forgotten to "ocean wave" '.
1928		R.J. Tasker Grimhaven 180: I’m heelin’ down to the Sidney Harbour’s for an ocean wave and a work-out on the bonny fair.
1932		‘P.P.’ Rhy. Sl. 13: Feeling ‘current cakey’ this morning, give us a ‘waterbury watch’ and I’ll have an ‘ocean wave’.
1946		St. Vincent Troubridge ‘Some Notes on Rhyming Argot’ in AS XXI:1 Feb. 47: ocean wave. A shave. (English.) Also rare, if English. Both mariner’s grave and digging the grave are more usual.
1960		J. Franklyn Dict. of Rhy. Sl.