Water in New Zealand and are of varying types and origins. Many of the lakes in the central North Island area are volcanic crater lakes, while the majority of the lakes near the Southern Alps were carved by glaciers. Hydroelectric reservoirs are common in South Canterbury, Central Otago and along the Waikato River. Over 180,000 kilometres of rivers has been mapped in New Zealand, the longest being the Waikato River with a length of 425 kilometres and the largest river by volume is the Clutha River with a mean discharge of 533 cubic metres per second. New Zealand has many notable waterfalls, some of
Military history of New Zealand in New Zealand waters on several occasions in 1940, 1941, 1942, 1943 and 1945 sinking a total of four ships. At the outbreak of war, New Zealand still contributed to the New Zealand Division of the Royal Navy. Many New Zealanders served alongside other Commonwealth sailors in vessels of the Royal Navy and would continue to do so throughout the war. Not until 1941 was the Royal New Zealand Navy formed. Before then New Zealand men and ships had already been in action. On 13 December 1939 took part in The Battle of the River Plate as part of small