Could have been on its way to Harwich or Felixstowe for export. From the shape of the tight fitting plastic cover the cockpit had a canopy and the whole pod seemed symetrical.
To see Harvards with wet feet go to YouTube and type ‘water skimming stunt planes’ or paste /http://www.youtube.com/watch?v=FgkKP_fDsKc&feature=relatedImagine trying this for the first time. Anyone know where it is?