Unit 2 slowed for Unit 1 and 3 other small boats. Unit 2 accelerated after passing Unit 1 and began to push a large wake. Unit 1 pushed off the bank upon seeing Unit 2 approach and began to make way. Unit 1 drove into Unit 2's wake causing it to capsize in shallow water. Unit 1's operator was injured when his head was struck by the starboard of his vessel and the river bottom.  Unit 1 was in approximately 2 1/2 to 3 1/2 ft of water when he crossed the large wake. Unit 2 is possibly a large white yacht with NJ or RI on the rear.  Unit 1's passenger was ejected when the vessel capsize but was uninjured and was wearing a PFD. The 3 jon boats following Unit 1 were not negatively affected by any wake.