For much of August, the 2/48th Battalion had been in training for the Allied attack on Lae, in Papua New Guinea. The unit's objective was to land on a strip of land designated as "Red Beach", and then fight their way approximately west towards Lae. Following a bombardment by American destroyers, Derrick's wave landed on the beach with minimal casualties on 4 September. Ten days later, the 2/48th Battalion's C Company—led by Derrick's platoon—captured Malahang airstrip, before Lae fell to the Allies on 16 September. Derrick was scornful of the Japanese defence of Lae, and wrote in his diary that "our greatest problem was trying to catch up" with the retreating Japanese force.