UDT officers were mainly CEC. UDT 10 had 5 officers and 24 enlisted originally trained as OSS Maritime Unit: Operational Swimmer Group II, but the OSS was not allowed to operate in the Pacific Theater. Adm. Nimitz needed swimmers and approved their transfer from the OSS to his control. The MU men brought with the swimfins they had trained with and the Seabees made them a part of UDT attire as quickly as the Supply dept. could get them. In the Seabee dominated teams the next largest group of UDT volunteers came from the joint Army-Navy Scouts and Raiders school that was also in Fort Pierce. Additional volunteers came from the Navy's Bomb disposal School, Marine Corps and U.S. Fleet.