December 1943 to May 1944 : 12th Defense Battalion on Cape Gloucester

The light antiaircraft artillery of the 12th Defense Battalion on the deck of an LST approaching Cape Gloucester, New Britain, is poised to fire on Japanese aircraft. Department of Defense photo (USMC) 71623

By late March 1944, Daddy was still considered as part of the 41st Replacement Battalion, but was on his way to Cape Gloucester (arrived April 2, 1944.)  The 12th Defense Battalion, as part of the 1st Marine Division, had been there since the invasion on December 26, 1943.

From Condition Red: Marine Defense Battalions in World War II by Major Charles D. Melson :

Colonel William H. Harrison's 12th Defense Battalion supported the landing of the 1st Marine Division at Cape Gloucester, New Britain, in December 1943. The lodgment on New Britain marked the end of the Rabaul campaign -- and of participation by major Marine Corps units in the South and Southwest Pacific -- for the United States had decided to isolate and bypass the fortress instead of storming it. Radar operator Victor C. Bond, a member of Harrison's battalion at Cape Gloucester, remembered sitting on the exposed "plow seat" of an SCR-268, with 90mm guns barking nearby. "During an air raid," he said, "it was difficult to tell if all the noise and smoke was due to the 90mms or the enemy."

On New Britain, the 12th Defense Battalion suffered most of its casualties from typhus and other diseases, falling trees, and lightning. "There is no jungle in the world worse than in southwestern New Britain," a member of the 1st Marine Division declared. The effort to limit the effects of malaria, prevalent in the swamps and rain forest, involved the use of atabrine, a substitute for scarce quinine. The remedy required hard selling by medical personnel and commanders to convince dubious Marines to take a bitter-tasting medicine that was rumored to turn skin yellow and make users sterile. In a moment of whimsy Second Lieutenant Gerald A. Waindel suggested adapting a slogan used to sell coffee back in the United States: "Atabrine -- Good to the last drop."

 I've always liked the photo below.  How any enemy plane could have survived that is beyond me...

A violent barrage from the 12th Defense Battalion greets attacking Japanese aircraft over Cape Gloucester, New Britain. As the danger from Japanese surface ships diminished, the defense battalions became concerned with Japanese air raids. Photo courtesy of the U.S. Naval Institute