Green’s Dictionary of Slang

1. a canal boat.

1879		G.G. Hart E.C.B. Susan Jane 8: When sailing down the Erie we have never yet been passed / By ‘any old canaller’ for Susy’s very fast.
1887		Century Mag. (N.Y.) Aug. 487: Near the bow of each canaler was a lantern of uncertain hue [DA].

2. (also canawler) one who lives and works on a canal boat.

1830		Germantown Tel. 14 July 4/1: A Canawler asked his captain ‘what A.M. stood for after a man’s name?’ [DA].
1851		Melville Moby Dick (1907) 218: ‘Canallers!’ cried Don [...] ‘who and what are they?’ ‘Canallers, Don, are the boatmen belonging to our Grand Erie Canal.’.
1874		‘A.P.’ [Arthur Pember] Mysteries and Miseries 120: So I was accepted as a passenger-hand; and, having transported my ‘duds’ to the boat, and stowed them away in my quarters [. . .] I began life as a ‘canawller’.
1884		S.F. Chronicle Aug. n.p.: These clusters of canal-boats are substantially floating villages. The ‘canaler’s’ family is seen on deck [DA].
1893		Outing (N.Y.) Sept. 465/2: The ‘canalers’ were found to be a good-natured and kind-hearted set of men [DA].