international traffic). The Canadian Coast Guard and Royal Canadian Navy have commissioned a new ice breaker along with multiple offshore patrol ships to guard and patrol the waters. Dixon Entrance (Alaska and British Columbia) contains two water areas that are mutually claimed by Canada and the U.S. A line known as the "A-B" Line was defined in a 1903 arbitration decision on the Alaska/British Columbia boundary. The court specified the initial boundary point (Point "A") at the northern end of Dixon Entrance and designated Point "B" 72 NM to the east. Canada relies on the "A-B" line as rendering nearly all of Dixon Entrance as its internal waters. The U.S. does not recognize the "A-B" line as an official boundary, instead regarding it as allocating sovereignty over the land masses within the Dixon Entrance, with Canada's land south of the line. The U.S. regards the waters as subject to international marine law, and in 1977 it defined an equidistant territorial line throughout Dixon Entrance, mainly to the south of the "A-B" line. The intersecting lines create four separate water areas with differing claim status. The two areas south of the "A-B" line (about and in size) are claimed by both countries. The other two water areas are north of the "A-B" line and are not claimed by either country. The two unclaimed areas are about and in size. In addition, Nunez Rocks is a low-tide elevation (LTE) ("bare at half-tide") that lies south of the "A-B" Line, surrounded by the sea territory claimed by the U.S. The United States has not ratified the Law of the Sea Treaty, although it adheres to most of its principles as customary international law. Under the treaty, LTEs may be used as basepoints for a territorial sea, and the U.S. uses Nunez Rocks as a basepoint. As a non-signatory, however, there is nothing preventing the U.S. from claiming areas beyond the scope of the Law of the Sea Treaty. The fact remains that, for about half of each day, above-water territory that Canada regards as Canadian is surrounded by sea territory that the U.S. has declared to be American. Historical disputes Alaska boundary dispute (Alaska/British Columbia and Yukon) lasted 1821 to 1903 Atlin District Bering Sea Arbitration lasted 1881 to 1893. Aroostook War (Maine/New Brunswick), a bloodless dispute that lasted from 1838 to 1839, leading to the Webster–Ashburton negotiations. Republic of Madawaska (Maine/New Brunswick),