Which branch of the military did the NCDUs primarily support during WWII?

The Naval Combat Demolition Units (NCDUs) primarily supported the Navy during World War II. Their key role was to clear obstacles from beaches and prepare landing sites for amphibious assaults, which were critical to the Navy's operations in major campaigns such as the invasions of Normandy and the Pacific islands. NCDUs were established to enhance naval operations by ensuring that naval forces could approach shorelines without encountering enemy defenses. This direct support of Navy operations made them an indispensable part of amphibious warfare, highlighting the close coordination between NCDUs and Navy forces.

While other branches, like the Army and Marines, conducted land operations, the unique focus of the NCDUs on seaborne assault preparation clearly aligned them with Navy objectives throughout the war. The Coast Guard, while also serving in various support roles, did not have the same direct relationship with NCDUs in terms of primary operational support.