She was in commissioned service in the United States Navy as the patrol vessel USS Cedar from 1917 to 1919 during and in the immediate aftermath of World War I.

Cedar was constructed in 1916–1917 by the Craig Shipbuilding Company in Long Beach, California, for the United States Lighthouse Service.

[2] Commissioned into Navy service as USS Cedar, she operated as a patrol vessel in the Thirteenth Naval District in the Pacific Northwest.

[5][6] The largest all-weather ship in the vicinity and the only one large enough to take off all of Princess Sophia′s passengers and crew, Cedar was 66 nautical miles (122 km; 76 mi) away.

[7] Cedar got underway from Sentinel Island in an attempt to reach her, but conditions were so extreme that she was herself in danger, and after 30 minutes she had to turn back.

Sometime around 17:50, Princess Sophia slipped off the reef and sank with the loss of all 343 people aboard, the worst maritime disaster in the combined history of Alaska and British Columbia.

After the 12-gross register ton motor vessel Anna Helen suffered a gasoline explosion and caught fire when her gasoline engine backfired at the junction of Icy Strait and Lynn Canal in the Alexander Archipelago in Southeast Alaska about 2 nautical miles (3.7 km; 2.3 mi) outside the entrance to Funter Bay on 22 October 1928, Cedar and the motor vessel Gloria responded to render assistance.

[4] Returned to U.S. Coast Guard control after the conclusion of World War II, Cedar was stationed at Kodiak, Territory of Alaska.