the wingspan from , modified the struts, floats and hull, and changed the way the engines were fitted. For the 1923 contest, two of the three British entrants were irreparably damaged before the race, leaving the Sea Lion III to compete alone. The United States team, flying Curtiss seaplanes, dominated the competition, with the winning pilot, David Rittenhouse, managing to reach a top speed of . Supermarine S.4 (1925) Even whilst the Sea Lion II was being modified at the Woolston works, Mitchell was working on a new plane, as Supermarine knew the American monoplane was the best design then available. The Supermarine S.4—the name was designated by Mitchell, with "S" standing for Schneider—was a joint Napier/Supermarine venture. The Supermarine team was backed by the Air Ministry, and had greater freedom than was given by the US government to their designers. The S.4 was described after Mitchell's death as "his first outstanding success". He used the practical experience gained when he designed its successor, the Supermarine S.5. Mitchell was fully aware of the need to reduce drag to increase speed. His new design for was a mid-wing, cantilever floatplane. It was comparable to a French monoplane, the Bernard SIMB V.2, which broken the flight airspeed record in December 1924. The S.4 lacked the newly-designed surface radiators, at that time still unavailable, but it was aerodynamic and aesthetically pleasing. Trial speeds reached and created a sensation in the press. The S.4 crashed before the 1925 race, for reasons that were never clearly established. On the day of the navigation trials it stalled before falling flat into the sea from . When the pilot Louis Baird was rescued by a launch, Mitchell, who was on board the rescue launch, jokingly asked the injured man: "Is the water warm?" 1926 and 1927 competitions The Air Ministry, the Society of British Aircraft Constructors and the Royal Aeronautical Society (RAeS) decided against challenging for the Schneider Trophy in 1926, but Mitchell was able to confirm that Supermarine would be ready for the race. His work at the NPL started in November that year. From wind tunnel tests at the NPL he learned that the S.4’s radiators had created a third of the aircraft’s total drag, and without this it would have been the most streamlined aircraft in the world. British aircraft companies intended to produce entries for the 1926 race, but the nature of the