On April 11, 2013, about 1500 eastern daylight time, an experimental amateur-built Searey, N92319, incurred substantial damage during a water taxi, and control binding and additional substantial damage after the subsequent takeoff from Lake Agnes, Polk City, Florida. The private pilot and the passenger were not injured. Visual meteorological conditions prevailed. No flight plan had been filed for the flight, between Lake Agnes and Florida Flying Gators Ultralight Flightpark (3FD4), Groveland, Florida. The personal flight was conducted under the provisions of 14 Code of Federal Regulations Part 91.According to the pilot, he taxied the airplane down a boat ramp, following a 1950's Piaggio twin-engine amphibian that weighed in excess of 6,000 pounds. The Piaggio took off, and the Searey then encountered a 2- to 3-foot wake. The pilot "quartered" the Searey into the wake, and when he did, the right side pitched up, and the left side pitched down. The pilot subsequently looked at the left horizontal stabilizer via a mirror on the airplane's left wing strut and conducted a full flight control check with no anomalies noted. He then took off, with the airplane bouncing once along the choppy water surface before becoming airborne. Once airborne, the pilot noted pitch control problems and was not able to level off the airplane until it reached about 1,800 feet. He was then able to descend the airplane at a rate of about 50 feet per minute by maintaining airspeed just above stall. The pilot circled the lake six times before being able to land. The landing included two bounces of the right wing, and during the second bounce, the right horizontal stabilizer was substantially damaged when it dragged through the water. Postflight examination of the airplane revealed a broken outboard left horizontal stabilizer tube which the pilot believed occurred during the wake encounter. It also revealed that the bolt connecting the three stabilizer cables had torn into the fabric, which the pilot surmised resulted in binding the control stick in a pitch-up position upon rotation.