The non-seaplane rated private pilot stated that his intention was to get comfortable with the airplane. He performed several maneuvers in the air, then seven uneventful touch-and-go water landings with half flaps extended. On the final landing attempt, he fully extended the flaps and had difficulty controlling the airplane. The airplane bounced on the water twice and the pilot initiated a go-around. The airplane veered left and was headed toward houses and boat docks; he maneuvered to ditch the airplane into the water to avoid a collision. The airplane impacted the water and sustained substantial damage to the wings and fuselage. The pilot egressed the airplane with minor injuries.