At 11:45 EDT, a Taylorcraft BC12D-4-85 on floats sank after landing on Saint Jeromes Creek. The pilot and the aviation safety inspector administering the seaplane rating test were not injured. The pilot and examiner agreed that the airplane touched down left float first and then the airplane abruptly pivoted left and sank. The examiner said the pilot touched down slightly flat and appeared to relax the controls a bit as the aircraft touched down. Post accident examination of the floats revealed heavy corrosion on some of the mounting bolts. The mounts and some crosstube segments were retained for examination.