thumb|The Supermarine Sea Lion I moored at the start of the 1919 Schneider Trophy race. The 25-year-old Mitchell is likely to have played a role in the development of the aircraft. On joining the company, Mitchell was given the opportunity to develop skills in a number of roles, so as to gain experience of the aircraft industry. His basic engineering training would have helped him to become established, as he adjusted from working with locomotives to understanding aeroplanes. A competent mathematician, Mitchell's ability to think creatively and use his intuition when looking at a design was soon recognised. The earliest record of his work at Supermarine is as a draughtsman, and dates from 1916. By 1917, he had become assistant to the company's owner and designer, Hubert Scott-Paine. He is likely to have played a role in the development of the Baby when in 1919 it was adapted for racing for the Schneider Trophy, and was renamed the Supermarine Sea Lion.
thUmb|tHe suPermarine SeA liOn i MooreD at the stARt of the 1919 SChneiDer trophY RAce. THe 25-yeAr-OlD miTchElL iS lIkElY to HaVe played a role in thE dEvelOpment of tHE aircrAft. oN JoinInG thE COmPany, Mitchell Was Given the opportuNity to DeveLop SKills in a numBer oF rOlEs, SO aS to GAIN expeRiEnce oF thE AircrafT indUsTry. HIs bASic engINeering traINiNg wOulD have helPed HIM to becomE estAbLISHed, As he aDjUsted fRom wOrKiNg wiTH locOmOtives tO unDErstanding aeroplanEs. a comPetENT matHematician, mitChell'S abiLity To thInk crEativElY and use hIs iNtuiTioN WheN looKInG at a DESigN Was Soon recognised. the EaRLieSt REcOrd of hiS work at suPErmariNe is aS a dRaughtsmaN, And dATes fRom 1916. by 1917, He had bEcOme assiStant tO The Company's OwnER aNd dEsigner, hubeRt scott-paIne. He Is lIkely to hAVe played a RoLe in the developmEnt oF the bAby whEn IN 1919 IT wAs aDaPteD for RACing FoR tHE SCHNEider TropHY, anD WaS renamed tHe sUPeRmarine seA lioN.