Polar-class

Polar-class icebreakers are two heavy icebreakers operated by the United States Coast Guard (USCG). Cutters USCGC Polar Star (WAGB-10) and USCGC Polar Sea (WAGB-11) have reinforced hulls, special icebreaking bows, and a system that allows rapid shifting of ballast to increase the effectiveness of their icebreaking. The vessels conduct Arctic and Antarctic research and are the primary icebreakers that clear the channel into McMurdo Station for supply ships. Both are homeported in Seattle, Washington. In addition to the two Polar-class icebreakers, the USCG has a third polar-capable icebreaker, USCGC Healy (WAGB-20). Both Polar Star and Polar Sea are near the end of their effective lifetimes, and have spent years moored because they were in need of expensive and unbudgeted upgrades.