High Quality Content by WIKIPEDIA articles! The Supermarine S.6B was a British racing seaplane developed by R.J. Mitchell for the Supermarine company to take part in the Schneider Trophy competition of 1931. The S.6B marked the culmination of Mitchell`s quest to "perfect the design of the racing seaplane" and was the last in the line of racing seaplanes developed by Supermarine and followed the S.4, S.5 and the Supermarine S.6.