Sir William Hamilton
New Zealanders like to think of themselves as practical people, the sort who can build anything with some lengths of 4'x2' and No.8 fencing wire. Nobody exemplifies this better than Bill (later Sir William) Hamilton, a farmer and self-taught engineer who in the 1950s invented the first practical jet boat so that he could navigate the shallow, braided rivers of the South Island.
Bill Hamilton was born in 1899 on the remote Ashwick Station (high country farm) near Fairlie in South Canterbury, and area carved by mighty rivers flowing from the Southern Alps. As a young manc he moved to Irishman's Creek, a 9,500 hectare station in Otago, which he purchased with a loan from his father. There he built himself a workshop and started a business building construction equipment of his own design. The business prospered and saw the Hamilton family through the hard years of the 1930s Depression. After World War II the business continued to thrive and was moved to Christchurch, leaving Hamilton more time to devote to his other interests: boats and speed. The workshop at Irishman's Creek became his centre for research and development, where Hamilton was the archetypal Kiwi inventor, a "bloke in a shed".
During the 1920s Hamilton had become fascinated with the new sport of motor-racing. He purchased a Bentley racing car on a trip to England in 1923 and began racing competitively. In early 1924 he returned home to Irishman Creek with his new bride, Peggy Wills, an English girl who shared Bill's love for the outdoors. Back home, Hamilton won the 50 mile NZ Motor Cup in 1925 and went on to claim the Australasian speed record in 1928, becoming the first person in the Southern Hemisphere to officially clock over 100mph. In 1930 he took his Bentley to England for the Brooklands Easter meet where he won all his races - the first driver to do so.
During the 1950s Hamilton revisited a boyhood idea of creating a boat that could to navigate the shallow waters around his home. In 1953, at the suggestion of Christchurch boat-builder Arnold France, he investigated an American design called the Hanley Hydro Jet, which drew in water and fired it out through a steerable nozzle underneath the boat. But even when further adapted, this design did not work well. Bill's own first craft, a 12 foot plywood boat fitted with a centrifugal pump and a Ford engine, could barely make way against the fast running currents around Irishman's Creek. In addition, because the jet nozzle extended below the hull it was prone to damage in the shallow rivers.
A breakthrough came in 1954 when an employee at Irishman's Creek suggested to Hamilton that he should move the nozzle of the jet above the boat's waterline, guessing that this would increase the effective thrust. Hamilton did so and systematically improved the design of his pumps. When he took one of his early demonstration boats to the USA, the media scoffed at his plan to take it up the Colorado River, but in 1960 a Hamilton jet became the first boat to travel through the Grand Canyon. The modern jet boat was born.
Bill Hamilton never claimed to have invented the jet boat, crediting instead "a gentleman named Archimedes, who lived some years ago". He retired from Hamilton Jet, the company he formed to commercialise his designs, in 1965 and was knighted in 1974. He died in 1978. You can read more about his remarkable life in this article (PDF, 3MB) from NZ Geographic.