Seriously now did you really think that I meant that they discriminated by virtue of the individual's nationality?
You paid according to the license plate on the vehicle. Ask anyone you happen to know in Alberta that has visited Victoria.
Seriously now....I drove my friend's Seattle plated car to Bowen Island a couple of years ago as they'd arrived by boat and pre-positioned their car at my place in Vancouver. I didn't pay any more than if it were my own BC plated car. The nice thing is you only pay one way...it's free to return. They arrived on their own boat, left it moored in the marina for the winter, and didn't pay to return on the ferry...not a bad deal.
Here is an archive of BC Ferry fares going back to 2008...nowhere does It mention discriminatory pricing based on vehicle license plates.
http://www.bcferries.com/travel_planning/fares/archive.html
You friends from Alberta may have been confused and gone on the Washington State Ferry system but I don't think they discriminate either...I've often travelled on them with my BC plates and not found any price differential.