Harry Louis Moffatt was born in London, England, probably in 1839. His father was John Anderson Moffatt, a Scot, who joined the British Army during the Napoleonic wars and became batman to Lord Aylmer; he married Eliza Ann Bosquet, a French orphan, who was Lady Aylmer's personal maid. Harry was the eldest of their four children. He went to sea at the age of 12. Although Harry can have had little formal education, he was an avid reader, especially of sea stories. In 1858 and 1860 he attended two courses at a navigation school in London, and qualified as a mate. His early experience at sea included being robbed of his clothing and equipment, a shipwreck and a South American revolution. He received no nautical instruction in spite of his parents' having paid a premium for his apprenticeship.
Harry Moffatt visited New Zealand in 1859 and returned in 1860. After a short spell on coastal vessels he and a friend decided to try gold-digging at Collingwood, near Nelson. In 1861 he was with a small party at the mouth of the Buller River when news came of the spectacular finds in Otago. After a short spell there, the claim his party was working was swept away in a flood and he returned to Nelson. His party then tramped to the Mangles and Matakitaki goldfields, where a number of diggers were working. After another brief trip to Otago they returned to prospect the Matakitaki. When news came of the Wakamarina find, they joined the rush and 'struck it lucky' for the first and only time. On the proceeds Moffatt was able to sail to England, this time as a passenger, in late 1864.
He returned to Nelson on the Magna Bona on 21 March 1865 and married Theresa Brown, whom he had met on board, in the Wesleyan Chapel at Nelson on 20 December 1865. They were to have four children, two girls and two boys. After about six years on coastal steamers, Moffatt took a shore job as a storekeeper on the Collingwood goldfields. In 1877 he became wharfinger and harbourmaster at the small port of Motueka, in the Nelson province. He remained there until he retired in 1911.
Moffatt's varied career is comparable to that of many early goldminers. He made no important discoveries and no fortune, but he remained in New Zealand and was a good citizen. However, he is distinguished by his writings. In 1896 he wrote a series of articles for the Nelson Evening Mail. These were subsequently published in a small booklet called A Nelson digger, under the pseudonym 'Kiwi', and have been used extensively by historians of the South Island goldfields. After his retirement he wrote the story of his life. Harry Moffatt died at Motueka on 20 May 1913. The manuscript of his autobiography was lost for many years, but Adventures by sea and land was eventually prepared for publication by his grand-daughter.