Green’s Dictionary of Slang

float up v.

[float v.1 (2)]

(N.Z.) to approach casually, to stroll up.

Press (Canterbury) 2 Apr. 18: ‘To be a dag at,’ ‘to put across a beaut,’ ‘to jerry to,’ ‘ducks’ breakfast,’ ‘to float up to,’ ‘to blow up to,’ ‘to sleep in the Star Hotel’ need no explanation.