The SS Otaki belonged to the New Zealand Shipping Company, a company whose ships ran passenger and cargo services between Great Britain and New Zealand.
During the war, it lost nine ships from a fleet of 32. This included the Rotorua I, a passenger steamer torpedoed and sunk on 22 March 1917, just 12 days after the Otaki.
During the Second World War 19 ships were lost from a fleet of 36, including Rotorua II, a cargo-passenger ship sunk on 11 December 1940.
New Zealand, a geographically remote island nation, relied heavily on the sea trade. Her ships and sailors played an essential role in WWI. New Zealanders worked both on British owned ships sailing to and from New Zealand, as well as for for native shipping companies. Like the British Merchant Navy, as part of the Empire, New Zealand merchant navy ships also flew under the Red Ensign. Their ships served as troop transports and hospital ships, as well as continuing to bring in vital supplies. The sea route took many ships and crews through the danger zone of the North Atlantic, where the German U-boats concentrated their attacks.
While the story of the Otaki and bravery of its crew became famous after the war, the worst loss for the NZ Merchant Navy was the Aparima. Large and slow, it was used as a training ship before the war, and many cadets continued to serve, running troops and supplies to Britain.
On the night of 18/19 November 1917, the Aparima was sailing towards Wales when a German torpedo hit its stern, sinking it almost at once. Of the 110 men aboard, also including many Indian lascars amongst the crew, 56 were lost. Of the 30 cadets on board, 17 died, of a total 24 New Zealanders lost.