Thanks. That makes sense and looking harder I can seem to see a tinge of blue along the upper edge

Hi Neale, the photo was taken during sunset. Could it be the cause from the sunlight ? Cheers.

Going by the newspaper article and its photo the funnel is a dark blue though here it looks black [on my monitor].

Funnel Nova Star Cruises Ltd see http://www.novastarcruises.com.

Background to service see https://bangordailynews.com/2013/11/18/news/portland/new-portland-nova-scotia-ferry-service-expects-to-carry-100000-passengers-its-first-year/