USCGC Polar Sea (WAGB 11)
The Council of Canadians was born later that summer and we quickly made our presence known. When the American icebreaker Polar Sea sailed without permission through Canadian waters, Council members dropped a Canadian flag onto its deck.
http://www.canadians.org/about/history/index.html
But the most direct challenge to Canada’s sovereignty in Arctic waters came in 1985, when the U.S. sent its icebreaker Polar Sea through the Northwest Passage without informing Canada or asking permission. The political skirmish that followed led to the 1988 Arctic Co-operation Agreement between the two countries. Boiled down to its essence, the agreement said the U.S. would not send any more icebreakers through the passage without Canada’s consent, and Canada would always give that consent. The wider issue of whether Canada’s Arctic waters were internal or international was left unresolved.
http://www.cbc.ca/news/background/cdnmilitary/arctic.html
video:
http://archives.cbc.ca/IDC-1-73-2349-13655/politics_economy/northwest_passage/clip7
