AFTER LANDING ON GLASSY WATER IN CALM WIND CONDITIONS, THE STUDENT PILOT LOST DIRECTIONAL CONTROL OF THE FLOATPLANE AND IT VEERED TOWARD THE SHORELINE. THE FLIGHT INSTRUCTOR MADE AN ABRUPT RUDDER PEDAL INPUT TO AVOID RUNNING AGROUND AND THE AIRCRAFT WATERLOOPED. THE RECENTLY CERTIFICATED FLIGHT INSTRUCTOR HAD ACQUIRED 14 HOURS OF FLIGHT INSTRUCTION EXPERIENCE, OF WHICH 6 HOURS WERE IN FLOATPLANES. THE STUDENT PILOT WAS MAKING HIS FIRST FLOATPLANE LANDING WHEN THE ACCIDENT OCCURRED.