Outside of the obvious fuel depots, some places do allow for the use of small amounts of bunker fuel. For example, in several coal-fired plants bunker C is analogous to kindling when you're building a fire. There isn't a continual release of GHGs and particulate from bunker C when using it in that manner. And that's the major issue with it. It not just the GHGs but the particulate as well. The British NHS estimates that at least 20,000 people in port cities across Britain die every year from ship stack emissions.
Of course the idea that it's not banned in Canada could be based on the fact that it isn't de jure banned. It could still be de facto banned like the death penalty was for over a decade before it became legislated policy. That way, coal-fired plants can still generate power until they're scheduled to be mothballed.
