That is a bit misleading,. There are bigger individual waves out there - for example;
"In February 2000, the British oceanographic research vessel RRS Discovery, operating in the Atlantic Ocean over the Rockall Trough west of Scotland, encountered the largest waves ever recorded by scientific instruments in the open ocean, with a significant wave height of 29.1 metres (95 ft) and individual waves up to 18.5 metres (61 ft)."