Combat Action Ribbon
Yangtze Service Medal
China Service Medal
American Defense Service Medal with "FLEET" clasp
Asiatic-Pacific Campaign Medal with one battle star
World War II Victory Medal
Philippine Presidential Unit Citation
Philippine Defense Medal
On 7 December 1941, Canopus, aging but able, lay at Cavite Navy Yard, as tender to Submarine Squadron 20. In the days that followed, her men worked day and night to repair ships damaged in the daily air raids as well as to keep her brood of submarines at sea. With the Army falling back on Manila, Canopus sailed to Mariveles Bay at the tip of Bataan on Christmas Day. On 29 December 1941 she received her first direct bomb hit. A 500-pound armor-piercing bomb penetrated all decks and exploded on the propeller shaft housing. Six sailors were killed mostly from scalding and fires started in the engine rooms and magazines. The six men were buried at sea at 1735 hours in Mariveles Bay at the tip of Bataan. On 1 January 1942 she received a second direct bomb hit. This time a fragmentation bomb which exploded near the top of the towering smokestack resulting in substantial damage to the ship and injuries to 16 men of the gun crews.
Disguised as a bombed out, listing, abandoned hulk, smoke pots were placed around the ship and giving the appearance of an abandoned hulk by day, while the ship hummed with activity by night. Her crew worked at a fevered pace repairing the smaller ships also left behind and keeping the submarines in action.
Just before the New Year, the last of the submarines left Canopus, but she never quit as she cared for small craft and equipment of the Army and Navy, sent her men into battle in the improvised naval battalion which fought on Bataan, and converted her own launches into miniature gunboats dubbed Mickey Mouse Battleships which attacked the Japanese moving south near the shore. But the overwhelming Japanese strength could not be held off forever, and upon the surrender of Bataan on the night of 8–9 April 1942, Canopus was ordered scuttled in Mariveles Bay, Bataan, to deny her use to the enemy. On 9 April, she was backed off into deep water under her own power and the veteran whom the Japanese could not sink ended a lifetime of service to the Navy when she was laid to rest by her own men.
221 of her crewmen were evacuated to Corregidor on 28 February 1942 and served with the Marines 1st, 2nd, and 3rd Battalions on beach defenses. The final 327 crewmen were also evacuated to Corregidor and served in the 4th Marine Regiment's 4th Battalion Reserves (Provisional) which fought gallantly during the final battle for the island fortress. Nearly all Canopus crewmen were captured at the fall of Corregidor and spent the rest of the war in Japanese POW Camps in the Philippines and the Asian mainland.