USCGC Modoc (WPG-46) was a 240-foot Tampa-class United States Coast Guard cutter designed for multi-mission roles.

With the breakout of war she was armed with depth charges, additional guns, sonar, and radar and transferred to the Navy.

Based upon her position, a PBY patrol bomber from RAF's 209 Squadron went on to locate Bismarck in time for HMS Ark Royal to launch the air attacks that ultimately disabled her and enabled the British fleet to catch up and sink her.

Modoc was launched as a Coast Guard cutter by Union Construction Company in Oakland, California on 1 October 1921.

For much of the next 18 years, she and another cutter alternated on 15-day patrols off the Grand Banks, using Halifax, Nova Scotia, and Boston as their bases.

Ships of the patrol were also expected to discover and destroy enemy weather and radio stations in Greenland, continue hydrographic surveys, maintain communications, deliver supplies, and conduct search and rescue operations.

They endured much discomfort amid the dangers of fog, storms, ice, and German raiders, but their work was vital to victory in the Atlantic.

[1] In both World Wars, when submarines were more of a menace than icebergs, the International Ice Patrol was suspended so that the cutters could perform more important escort duty.