After 9 years of panache and service to the upper crust from both sides of the Tasman, she was refitted and was enlisted in the Navy as a hospital ship for service in the First World War.

Some 25,000 sick, wounded and dying soldiers were valiantly transported and cared for as she traversed the English Channel over the five years of her military service. After the war, she was returned to her former glory as a luxury liner, and made six New Zealand to England voyages. But the advent of internal combustion engines, ironically improved by the war, lead to her demise as newer, faster and cleaner vessels took to the high seas, leaving the Maheno in their wake.