It is in fact the Halifax Port Authority's work boat Maintainer 1.
On July 14, 2002 it was struck by the ship Esperanza, and pinned against the pier. On February 16, 2003 it sank at its berth at pier 25 when a through hull fitting froze and burst. In both cases it was repaired, and in the latter the engine exhaust was re-routed through the cabin top.
Just for comparison puropses, here is a fishing boat:
CCGS Sir William Alexander passes Ives Knoll outbound in the background.