Eric Milton Denby was born in Warkworth but lived most of his life in Northcote, Auckland. He trained as an engineer and in WWI was posted to the NZ Field Artillery. He survived a gunshot wound to the scalp in Ypres in 1917 but was adjudged no longer physically fit for military service. He later joined the Dunedin-based Union Steamship Co. of New Zealand Ltd as an engineer and his maritime career with the company was marked by at least two significant events, both sinkings.

On 19 August 1930, Denby was third engineer on the RMS Tahiti when she sank near Rarotonga en route from Wellington to San Francisco, following a holing two days previously caused by the breaking of a propeller shaft. All were rescued.

On December 8 1940 Denby was second engineer onboard the SS Komata when she was sunk off Nauru by the German raider Komet. Most of the crew were rescued and taken on board to join the survivors of other cargo & passenger vessels sunk over the previous month by the raider and her two fellow hunters. Denby was one of nearly 500 captives eventually marooned by the Germans on Emirau Island.