Ah I see the confusion - that overflight wave tolerance is defined by an emergency landing condition. In the extremely low probability chance that the seaglider needs to perform an emergency landing, the passengers need to be safe. That defines the 8-13ft window.

In no cases are we contouring waves in flight. We fly straight and level. Typical flight altitudes are 10-30ft above the wave peaks. The waves are well below us.