The tow supply vessel Aiviq travels just under 2 mph with Royal Dutch Shell’s conical drilling unit Kulluk in tow 116 miles southwest of Kodiak City, Alaska, Dec. 30, 2012. The Aiviq towed the Kulluk in tandem with the tug Nanuq. (U.S. Coast Guard photo by Petty Officer 2nd Class Chris Usher/Released)

A commercial icebreaker being purchased by the U.S. Coast Guard will be officially homeported in Juneau, the culmination of a years-long effort to…