The fourth episode in the series visits the fast, furious and all-too-often deadly powerboat races of the 1920s and 30s. In the biggest spectator sport of the time, the fastest men on water competed in gladiatorial combats in front of crowds of up to a million spectators.
The Harmsworth Challenge was the America's Cup of the powerboat world, with intense rivalry between Britain, who relied on technological ingenuity, and America, who put their trust in boats powered by immensely powerful aircraft engines. It was a David and Goliath confrontation, which was only put aside when World War II loomed. But the powerboat technology survived to be adopted by the military, spawning the Royal Navy's fleet of speedy Motor Torpedo Boats and the US Navy's legendary PT patrol boat.
Using previously unseen archive footage and personal testimony from those who were there, Speed Machines tells the story of this golden age of powerboat racing.