The pilot reported that during takeoff from a lake, the airplane started to bounce from wave to wave and eventually developed into a porpoise. As power was reduced to abort the takeoff, the left wing tip ski struck a wave and the airplane yawed to the left. The right wing then struck the water and the airplane came to an abrupt stop. The fuselage and wing spars were substantially damaged. The pilot reported that the wind on the lake at the time of the accident was about 18 knots and the waves were about 12-15 inches high. The pilot reported that prior to this; the largest waves the airplane has encountered were 10-12 inches high. The pilot reported no mechanical failures or malfunctions with the airplane that would have precluded normal operations.