Sydney Harbour, Fleet Base East Garden Island. 5 January 2014.
Under disused hammerhead crane, soon to be removed.
See Google Earth 33°51'45.24" S 151°13'30.00" E

Data from Wikipedia :
Name: USCGC Polar Star
Builder: Lockheed Shipbuilding and Construction Company, Seattle, WA
Commissioned: 1976
Refit: Vigor Industrial shipyard, Seattle, WA (March 2010-December 2012)
Nickname: Building 10, Polar Spare, Brand X, Wide Ass Government Building, Red Tubs of Fun[1]
Status: Reactivated (March 11, 2010)
General characteristics [2]
Class & type: Polar-class icebreaker
Displacement: 10,863 long tons (11,037 t) (standard)
13,623 long tons (13,842 t) (full)
Length: 399 ft (122 m)
Beam: 83 ft 6 in (25.45 m)
Draft: 31 ft (9.4 m)[3]
Installed power: Six Alco 16V-251F diesel engines (6 × 3,000 hp)
Three Pratt & Whitney FT-4A12 gas turbines (3 × 25,000 hp)
Propulsion: Combined diesel-electric or gas (CODLOG)
Three shafts; controllable pitch propellers
Speed: 18 knots (33 km/h; 21 mph)
3 knots (5.6 km/h; 3.5 mph) in 6-foot (1.8 m) ice
Range: 16,000 nautical miles (30,000 km; 18,000 mi) at 18 knots (33 km/h; 21 mph)
28,275 nautical miles (52,365 km; 32,538 mi) at 13 knots (24 km/h; 15 mph)
Complement: 15 officers
127 enlisted
33 scientists
12-person helicopter detachment
Aircraft carried: 2 HH-65A Dolphin helicopters

Vessel website : http://www.uscg.mil/pacarea/cgcpolarstar/default.asp

Voyage purpose from http://www.military.com/daily-news/2013/12/04/coast-guard-icebreaker-deploys-to-antarctica.html
U.S. Coast Guard | Dec 04, 2013
SEATTLE – Coast Guard Cutter Polar Star departed Coast Guard Base Seattle for Antarctica, Tuesday, in support of Operation Deep Freeze for the first time since 2006 with the task of resupplying the National Science Foundation Scientific Research Station in McMurdo

The deployment of USCG Polar Star (WAGB-10) is the first since the ship was taken out of mothballs and underwent a $90 million overhaul.

ADDED LATER
This pic was taken just before departure to assist trapped Russian and Chinese icebreakers

See http://www.navytimes.com/article/20140105/NEWS03/301050011/USCG-icebreaker-rescue-2-ships-Antarctica

This includes "The Russian research ship Akademik Shokalskiy has been trapped in ice-clogged Commonwealth Bay since Christmas Eve, while the Chinese ship which came to its rescue, Xue Long or Snow Dragon in Chinese, reported on Friday it too had become stuck nearby.