CBU 421

**CBU 421** (Construction Battalion Unit 421) is a United States Navy Seabee unit that was established during World War II as part of the Navy’s effort to rapidly construct and maintain advanced bases in the Pacific Theater. The unit was tasked with building airfields, roads, and support facilities, often under hostile conditions and close to the front lines. After the war, CBU 421 supported various peacetime and Cold War operations, providing crucial engineering and construction expertise to both military and humanitarian missions. Over the decades, the unit has maintained a legacy of adaptability and excellence, exemplifying the Seabees’ motto: “We Build, We Fight.”