The race on the following day was won by the British team, with N247 coming first at a speed of 328.63 miles per hour (528.88 km/h), whilst N248 set World closed-circuit records for 50 and 100 kilometres (31 and 62 mi).

[3] The engine, an adaptation of the Rolls-Royce Buzzard,[6][note 2] was designed and manufactured by 4 May, but this machine was found to overheat after 15 minutes.

The time between overhauls was able to be lengthened to five hours when the fuel was diluted, and the engine power was able to be increased to 1,900 hp (1,400 kW) at a frequency of 3,000 rpm.

[3] The engine needed 160 imperial gallons (730 L; 190 US gal) of petrol to complete a race, as it consumed fuel at a rate of 3.6 imp gal/min (0.27 litres per second).

[8] To help alleviate problems of engine cooling caused by the high rate of heat generation, the S.6 had surface radiators built into the floats as well as on the wings.

[5] The new engine weighed 1,530 pounds (690 kg), a weight that meant that it had to be better supported by moving the float struts forward by a slight amount.

[10] Soon after N247 arrived at Calshot, it was found that one of the floats was so low in the water on take-off that it made the aircraft rotate on the surface.

[12] The 1929 Schneider Trophy race took place off the English coast north of the Isle of Wight, under ideal weather conditions, and with at least a million people assembled along the beaches to witness the event.

N248 was disqualified when it turned inside one of the marker poles, but nonetheless, set World closed-circuit records for 50 and 100 kilometres (31 and 62 mi) during its run.

[5] Following the victory, the British Prime Minister Ramsay MacDonald publicly pledged official support for the 1931 contest, a decision that was later reversed by the government.

[13] For the 1931 Schneider Trophy race, also to be held at Calshot, the S.6 was adapted to take a more powerful 2,350 horsepower (1,750 kW) version of the R engine.

[14] During the initial flight of the improved N247 on 2 June, the pilot experience dangerous levels of tail flutter (a form of resonance), which was only alleviated when masses were fixed to the rudder.